Literature Review
Writing Services
Critical synthesis, not summary. From PRISMA-compliant systematic reviews to theoretical frameworks for doctoral dissertations — our PhD consultants identify research gaps that justify your study.
Critical Appraisal and Synthesis, Not Summary
A literature review is the foundation of every credible research project. It situates your study within existing knowledge, demonstrates that you have identified a genuine gap or problem, and establishes the theoretical and empirical basis for your methodology and research design.
According to research published in the Journal of Evidence-Based Medicine, literature reviews are categorised by the question they answer: systematic reviews address specific clinical or empirical questions with reproducible protocols, while scoping and narrative reviews map broader bodies of evidence.[1] Selecting the wrong review type is one of the most common reasons supervisors reject a dissertation chapter.
We use a synthesis matrix — a structured table mapping sources against key themes, methodologies, populations, and findings — to move beyond annotation into genuine critical comparison. The result is a review that identifies where researchers agree, where they contradict each other, and what has not yet been studied.
[1] Munn, Z. et al. (2018). Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Medical Research Methodology. ncbi.nlm.nih.gov/pmc/articles/PMC8197294/
Methodological Framework
Inclusion and Exclusion Criteria
Before searching, we define clear eligibility criteria: publication date range, language, study design (RCTs only, or observational studies included), geographic scope, population characteristics, and outcome measures. These criteria are documented in the methodology section so your review is transparent and reproducible.
Critical Appraisal and Bias Assessment
Each source is evaluated using appropriate appraisal tools: the Cochrane Risk of Bias tool for RCTs, the Newcastle-Ottawa Scale for cohort studies, the CASP checklist for qualitative research, and the AMSTAR-2 tool for existing systematic reviews. We document funding sources, sample size adequacy, and validity threats for each study.
Thematic Synthesis and Gap Identification
Sources are grouped thematically — not listed chronologically. We identify converging findings, contested positions, and understudied variables. The research gap statement positions your study as a direct and necessary response to what the existing literature has failed to address, producing a compelling rationale for your methodology.
Six Types of Literature Reviews
Each review type serves a different research purpose. Selecting the correct type at the outset determines how the review is structured, what databases are searched, and what quality appraisal tools are applied.
Narrative Review
A narrative review provides a comprehensive critical analysis of current knowledge on a specific topic, structured around themes, debates, or chronological development rather than a rigid search protocol. Unlike systematic reviews, it allows the author’s expert judgment to determine which sources are most illuminating, making it particularly effective for humanities, social sciences, and policy analysis where context and theoretical lineage matter as much as empirical data.
We structure narrative reviews with a clear introduction that contextualises the topic historically, body sections organised by theme or conceptual strand rather than by author or date, and a conclusion that synthesises the key debates and identifies where your study intervenes. Every claim is supported by in-text citations from peer-reviewed sources retrieved from relevant databases.
Systematic Review
A systematic review is the highest level of evidence synthesis. It uses a fully documented, reproducible methodology to answer a precisely defined research question by identifying, appraising, and synthesising all relevant studies meeting specified eligibility criteria. We adhere strictly to the PRISMA 2020 guidelines (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which require documentation of every stage of the search and selection process.
Our systematic review service includes: a registered or pre-specified protocol on request, structured database searches with documented search strings in MEDLINE, Embase, CENTRAL, CINAHL, or PsycINFO, dual independent screening of titles and abstracts against inclusion criteria, full-text review of eligible studies, quality appraisal using validated tools, data extraction into standardised tables, and a PRISMA 2020 flow diagram. The narrative synthesis integrates findings across studies to answer the review question.
View Nursing Reviews →Scoping Review
A scoping review maps the extent, range, and nature of evidence available on a broad or emerging topic. Unlike systematic reviews, scoping reviews do not exclude studies on quality grounds — they aim to provide a comprehensive map of what exists. This makes them appropriate for clarifying key concepts and definitions, identifying and analysing knowledge gaps, and informing whether a full systematic review is feasible or warranted.
We follow the Arksey and O’Malley (2005) framework extended by Levac et al. (2010), covering: framing the research question using PCC (Population, Concept, Context) or PICO elements, developing an iterative search strategy, charting data from included studies into extraction tables, and presenting results as a narrative account of the evidence landscape. Scoping reviews are increasingly required in health sciences, education, and policy research as standalone publications.
Theoretical Review
A theoretical review traces the genealogy of key concepts, models, and paradigms within a discipline. It is not primarily empirical — it analyses how theories have been defined, operationalised, challenged, extended, and contested over time. This type of review is essential for dissertations that aim to propose new theoretical constructs, apply existing theory to a new context, or critique dominant frameworks.
We identify the foundational texts and seminal authors for your theoretical area, map the lineage of the concept from its original formulation to contemporary usage, document the major critiques and counter-arguments within the debate, and position your study’s theoretical stance explicitly within that map. Social science, education, law, philosophy, and management dissertations most commonly require this review type as their literature chapter.
View Theory Services →Annotated Bibliography
An annotated bibliography provides a formatted reference list where each entry is followed by a concise analytical annotation — typically 100–200 words — summarising the source’s purpose, methodology, key findings, and relevance to the research topic. Unlike a full review, it does not synthesise sources with each other, but it serves as a critical inventory of the literature and is frequently submitted as a standalone assignment or as a preliminary stage before writing the full review.
Each annotation we write covers: a brief description of the source’s argument and method, an evaluation of the source’s credibility, limitations, and peer-review status, and an explanation of how it contributes to your specific research question. We format all references in the referencing style specified — APA 7, MLA 9, Chicago, Harvard, Vancouver, or OSCOLA — with hanging indents and correct punctuation throughout.
Meta-Analysis
A meta-analysis applies statistical methods to pool quantitative data from multiple independent studies, producing a combined effect size estimate with greater statistical power than any individual study. It is the quantitative component of a systematic review and is considered the highest level of evidence in clinical and behavioural research. Our biostatisticians extract numerical data (means, standard deviations, odds ratios, relative risks) from primary studies and perform the meta-analysis using RevMan or R (metafor package).
The statistical outputs include: pooled effect size with 95% confidence intervals displayed in a forest plot, heterogeneity assessment using I² statistic and Cochran’s Q test, subgroup analyses by population, intervention type, or study design, funnel plot for publication bias assessment, and Egger’s test or trim-and-fill adjustment where bias is detected. The written narrative interprets all statistical findings in clinical or practical context.
View Statistics Services →Database Access and Search Strategy
High-quality literature reviews depend on comprehensive, systematic searching — not ad hoc Google Scholar queries. Our writers hold institutional or subscriber access to the major academic databases used across all disciplines, ensuring no relevant studies are missed.
Search strings are constructed using Boolean operators (AND, OR, NOT), Medical Subject Headings (MeSH terms) for biomedical databases, thesaurus terms for EBSCO platforms, and controlled vocabulary from each database’s own taxonomy. Searches are run in at least two independent databases and supplemented by citation tracking (forward and backward) of high-impact papers to capture sources not indexed in standard databases.
The PRISMA statement, which provides the authoritative reporting standard for systematic reviews and meta-analyses, is published and maintained at prisma-statement.org and documents the full flow from records identified through search to studies included in the final synthesis.[2] We use this framework for every systematic review we produce.
[2] Page, M.J. et al. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. PRISMA Statement. prisma-statement.org
Databases We Search
Grey Literature
For systematic reviews, we also search grey literature sources including government reports, WHO databases, clinical trial registries (ClinicalTrials.gov, WHO ICTRP), and conference proceedings to reduce publication bias.
Writing a Literature Review: A 5-Step Process
If you are writing your own review, follow this structured process used by academic researchers to ensure methodological rigor and comprehensive coverage.
Search
Develop a structured search string using Boolean operators and controlled vocabulary. Query at least two independent databases.
Screen
Screen titles and abstracts against pre-defined inclusion and exclusion criteria. Document decisions in a PRISMA-compatible log.
Appraise
Critically appraise full-text sources using validated checklists (Cochrane RoB, Newcastle-Ottawa, CASP). Rate each study’s quality.
Map
Complete a synthesis matrix grouping sources by theme, population, method, and key finding. Identify where studies converge and conflict.
Write
Write thematically, not chronologically. Each paragraph should synthesise multiple sources around a specific argument or finding.
Stuck on Step 3 — Identifying the Research Gap?
The research gap statement is the hardest part of any literature review to write. Our PhD consultants analyse existing literature to pinpoint exactly where your study fits within the field — and why it is needed.
Disciplines We Cover
Literature reviews require subject-matter knowledge. Our writers hold postgraduate qualifications in the field they review, not just research methodology experience.
Health Sciences
Nursing, medicine, pharmacy, public health, physiotherapy, and psychology. Systematic reviews with PRISMA compliance, RCT appraisal, and clinical practice implications. CINAHL, MEDLINE, and Embase are the primary databases searched for health science topics.
Social Sciences
Sociology, psychology, criminology, political science, and anthropology. Theoretical and narrative reviews synthesising qualitative and mixed-methods studies. ProQuest Sociology, PsycINFO, and JSTOR are primary databases for social science literature searches.
Business & Management
Marketing, HRM, organizational behaviour, finance, supply chain, and entrepreneurship. Systematic and narrative reviews drawing on Business Source Premier, ABI/INFORM, and Emerald Insight for peer-reviewed management and business literature.
Education
Pedagogy, curriculum studies, educational psychology, TESOL, and higher education policy. Scoping and systematic reviews searched in ERIC (Education Resources Information Center), British Education Index, and Australian Education Index databases.
Law & Policy
Legal theory, comparative law, criminal justice, public policy, and international relations. Doctrinal and theoretical reviews drawing on Westlaw, LexisNexis, HeinOnline, and SSRN. OSCOLA, Bluebook, and AGLC referencing formats applied as required.
Engineering & Technology
Mechanical, civil, electrical, chemical, and computer engineering. Systematic and scoping reviews on technology applications, materials, and manufacturing processes, searched in IEEE Xplore, Scopus, Web of Science, and the ACM Digital Library.
| Review Type | Primary Use | Quality Appraisal | Fastest Delivery |
|---|---|---|---|
| Narrative Review | Humanities, social sciences, policy | Not required (expert judgment) | 24 hours (short) |
| Systematic Review | Clinical, health, education research | Cochrane RoB, CASP, NOS | 3–5 days |
| Scoping Review | Emerging topics, concept mapping | Not rated (all designs included) | 2–4 days |
| Theoretical Review | Dissertations, PhD thesis chapters | Source credibility assessment | 48 hours |
| Annotated Bibliography | Research planning, coursework | Per-source annotation | 12 hours |
| Meta-Analysis | Clinical trials, intervention research | Cochrane RoB + statistical | 5–7 days |
Global Academic Standards Compliance
Every institution specifies a referencing style and has expectations about structure, academic register, and critical depth. We write to meet your university’s exact requirements.
North American Standards
APA 7th edition is the standard for social sciences, nursing, and psychology. MLA 9th edition is required for humanities at most US and Canadian universities. Chicago 17th edition (Notes-Bibliography and Author-Date) is used for history, political science, and fine arts.
UK & European Standards
Harvard (Cite Them Right edition) is the dominant referencing system at UK universities for most disciplines. OSCOLA (Oxford University Standard for the Citation of Legal Authorities) is required for law. Vancouver numbering is standard for biomedical journals and medical school submissions.
Australian Standards
AGLC 4th edition (Australian Guide to Legal Citation) is required by all Australian law schools. Australian Harvard, as adopted by Group of Eight universities, is standard for many social science and business programmes. We follow each institution’s specific adaptation of these styles.
Thematic Structure
Sources are grouped and discussed by conceptual theme or argument strand, regardless of publication date. This is the most analytically rigorous structure and is required for most PhD dissertations and high-level academic papers.
Best for: Dissertations, journal articles
Methodological Structure
Studies are grouped and compared by the research method used — experimental vs. observational, qualitative vs. quantitative, longitudinal vs. cross-sectional. Commonly used in clinical and health science systematic reviews where methodology determines evidence quality.
Best for: Systematic reviews, clinical research
Chronological Structure
The literature is reviewed in chronological order to trace the evolution of a concept, theory, or field. This structure is appropriate when the historical development of an idea is itself the subject of the review, as in intellectual history or theory development chapters.
Best for: Theory reviews, intellectual history
From Brief to Delivery
Submit Your Brief
Provide your research question or topic, the type of review required, the word count, any source requirements (number of studies, date range, journals to include or exclude), referencing style, and submission deadline. The more specific your brief, the more targeted the review.
Writer Assignment and Confirmation
We assign a writer with a postgraduate qualification in your subject area. You receive a fixed quote based on the scope, level, and deadline. For systematic reviews, the writer will confirm the database search strategy with you before beginning.
Search, Appraise, and Synthesise
The writer conducts structured database searches, screens results, retrieves full texts of eligible studies, completes quality appraisal, and populates the synthesis matrix. The written review is produced from this analytical foundation — not from pre-existing text.
Delivery and Revision
You receive the completed review as a Word document, with the reference list in the specified style and, for systematic reviews, the PRISMA flowchart and synthesis matrix as appendices. Free revisions are available within 14 days if the work does not meet the original brief.
Urgent Literature Review
Annotated bibliographies and short narrative reviews (up to 5 pages) are available in 12 hours. Full systematic reviews require a minimum of 3 days. Submit your brief now and we will confirm availability before you pay.
Submit Urgent OrderWhat to Include in Your Brief
- Research question or topic statement
- Review type (systematic, narrative, scoping, theoretical, annotated bibliography)
- Required word count and number of sources
- Date range for source inclusion (e.g., 2015–2025)
- Referencing style (APA 7, Harvard, Vancouver, etc.)
- Any sources you have already identified
- Assignment brief or marking rubric if available
- Submission deadline (date and time zone)
Literature Review Pricing
All rates include database search, source retrieval, synthesis matrix, and one free revision round. Meta-analysis pricing includes statistical analysis in R or RevMan.
Written Reviews — Per Page
Specialist Services — Fixed
Full systematic reviews and meta-analyses are quoted individually after reviewing the research question and scope. Contact us before ordering.
PhD Research Consultants
Every literature review is written by a consultant with a postgraduate degree in the relevant subject. No generalist writers. No outsourcing.
Dr. Julia Muthoni
Systematic Reviews
PhD Biostatistics. Specialist in PRISMA-compliant systematic reviews and meta-analyses for nursing, medicine, and public health. Expert in Cochrane Risk of Bias assessment and RevMan statistical analysis.
Dr. Simon Njeri
Social Sciences
PhD Sociology. Specialises in theoretical frameworks, qualitative synthesis, and narrative reviews for sociology, criminology, and political science dissertations. Uses PsycINFO and ProQuest databases.
Eric Tatua
Engineering & Policy
M.Eng. Expert in scoping reviews for engineering, technology, and public policy topics. Searches IEEE Xplore, Scopus, and Web of Science. Experienced with Arksey-O’Malley and Levac scoping review frameworks.
Dr. Stephen Kanyi
Natural Sciences
PhD Physical Sciences. Handles literature reviews for physics, chemistry, and environmental science. Accesses PubMed, Web of Science, and ScienceDirect. Applies CASP checklists for quantitative study appraisal.
Dr. Michael Karimi
Business & Economics
PhD Economics. Writes literature reviews for management, finance, and economics dissertations. Accesses ABI/INFORM, Business Source Premier, and EconLit. Specialises in systematic and narrative reviews with thematic synthesis.
Research Outcomes
“The systematic review was accurate and complete. Dr. Julia included the PRISMA flowchart and the risk-of-bias table without being asked. My supervisor said the methodology section was one of the strongest she had seen from a student submission.”
Rachel K.
Nursing DNP, Year 2
“I had 40 sources and no idea how to connect them. The writer grouped everything thematically and the review told a clear story about how the field had shifted over the last decade. The marking feedback mentioned the ‘sophisticated critical engagement with the literature.'”
Mark T.
History MA, Dissertation Stage
“The scoping review covered engineering databases I wouldn’t have known to search. The synthesis table made it easy to see where the gaps in the literature were. The research gap statement gave my proposal a clear rationale that the panel accepted.”
Peter O.
PhD Engineering, Proposal Stage
“I ordered an annotated bibliography for 25 sources in Harvard style. Every annotation critically evaluated the source’s methodology and relevance — not just a summary. Delivered in under 24 hours with the correct hanging indent format throughout.”
Sophie B.
Psychology BSc, Year 3
Frequently Asked Questions
Yes. Every literature review includes a synthesis matrix — a structured table mapping each source to key themes, research methods, populations, and main findings. This ensures the written review is analytically grounded in a comparative framework rather than being a sequential list of summaries. We can deliver the matrix as a standalone Excel file on request.
Yes. Our writers have institutional or subscription-based access to ScienceDirect, EBSCO (CINAHL, Academic Search Premier), ProQuest, PubMed/MEDLINE, IEEE Xplore, JSTOR, Scopus, Web of Science, and Embase. We do not rely on open-access sources alone, which means we can retrieve full texts of studies that most students cannot access without a university library account.
Yes. All systematic reviews are conducted and reported according to PRISMA 2020 (Preferred Reporting Items for Systematic reviews and Meta-Analyses). This includes documenting the full search process in the PRISMA flowchart — records identified, duplicates removed, records screened, records excluded with reasons, and studies included in the final synthesis. We also complete the PRISMA 2020 checklist and provide it as a supplementary document.
Yes. Our PhD-level writers produce literature review chapters at the standard expected by doctoral supervisors and examiners. This means the review identifies a specific, well-justified research gap, situates your study within the existing theoretical and empirical literature, and critically engages with methodological debates in the field rather than merely summarising what has been published.
We format references in APA 7th edition, MLA 9th edition, Chicago 17th edition (both Notes-Bibliography and Author-Date variants), Harvard (Cite Them Right), Vancouver, OSCOLA, AGLC 4th edition, and IEEE. Specify your required style in the brief. If your institution uses a custom variation of a standard style, provide your department’s referencing guide and we will follow it precisely.
Annotated bibliographies of up to 15 sources can be delivered in 12 hours. Short narrative reviews of up to 1,500 words can be delivered in 24 hours. Full systematic reviews require a minimum of 3–5 days depending on the number of studies identified and the scope of the search. Rush orders are accepted subject to writer availability and incur a 50% surcharge.
A systematic review answers a specific, precisely defined question using a reproducible protocol that includes quality appraisal of included studies. Studies that do not meet quality thresholds may be excluded. A scoping review maps the breadth of available evidence on a broader topic without excluding studies on quality grounds — it aims to show what research exists and where gaps are, often as a precursor to deciding whether a full systematic review is feasible. Scoping reviews are appropriate when the field is emerging or when the question is too broad for a systematic review.
Yes. We write standalone theoretical framework sections identifying the key theories, models, and conceptual lenses relevant to your research topic, explaining their origins and historical development, and connecting them explicitly to your research questions and the study’s methodology. This is a common requirement for social science, education, and management dissertations where the theoretical framework sits as a distinct section either within or separate from the literature review chapter.
Build a Strong Foundation
Whether it is a 10-page systematic review for a nursing DNP or a 3,000-word theoretical framework for a social science dissertation — every review is handled by a qualified specialist.