What Citation Style Should I Use for My Thesis? (2026 Decision Guide)

Choosing the wrong citation style for your thesis is one of the fastest ways to lose marks before your examiner has even read your argument. If you are asking what citation style should I use for my thesis, the answer depends on three things: your academic discipline, your university’s regulations, and — occasionally — your supervisor’s personal preference. This guide cuts through the confusion with a clear decision tree, a full breakdown of every major style, and answers to the eight most common questions students ask in 2026.

The short version: most students in social sciences and education use APA, humanities students use MLA or Chicago, history and arts students use Chicago Notes-Bibliography, UK students often use Harvard, medical and health students use Vancouver, and engineering and computer science students use IEEE. But “most” is not a rule — so read on before you commit to a format.

Check Your University Guidelines First

Before consulting any discipline convention, open your university’s thesis submission handbook. Many programmes — especially at postgraduate level — mandate a specific citation style, and deviating from it is an automatic formatting fail regardless of the quality of your research. Look for phrases like “references should follow APA 7th edition” or “the department uses MHRA.”

If your handbook says nothing, email your supervisor and ask directly: “Does the department have a preferred citation style for theses?” Supervisors often have strong preferences even when the department does not publish a formal rule. Getting this wrong costs you credibility before the examiner reads a single finding.

Once you have confirmed there is no mandated style, use the decision tree below to pick the best fit for your discipline. Korean-speaking students can also consult this Korean-language guide to citation methods for native-language guidance.

The Citation Style Decision Tree

Follow the branches in order. Stop at the first match that fits your situation.

APA — Social Sciences, Psychology, Education

The Publication Manual of the American Psychological Association, now in its 7th edition (2020), is the most widely used citation style in academic research worldwide. It dominates psychology, sociology, education, nursing, social work, business, and economics programmes. The core principle is author-date in-text citations that pair with a full reference list at the end of the document.

In-text format: (Author, Year) or Author (Year) when the name is part of the sentence.
Example: Studies confirm that spaced repetition significantly improves long-term retention (Kornell & Bjork, 2008).

Reference list entry (journal article):
Kornell, N., & Bjork, R. A. (2008). Learning concepts and categories: Is spacing the “enemy of induction”? Psychological Science, 19(6), 585–592. https://doi.org/10.1111/j.1467-9280.2008.02127.x

Key APA rules for thesis writers:

• Use a hanging indent (0.5 in) for every reference list entry.
• List up to 20 authors; for 21 or more, use an ellipsis after the 19th name.
• Include DOIs as hyperlinks where available.
• Titles of articles and book chapters use sentence case; journal titles use title case.
• Running headers are no longer required in student papers under APA 7.

Use our step-by-step APA citation guide if you need detailed examples for every source type.

MLA — Humanities and Literature

The Modern Language Association Handbook, 9th edition (2021), is the standard for English literature, comparative literature, linguistics, film studies, and many cultural studies programmes — particularly in the United States. MLA uses a parenthetical author-page system rather than author-date, reflecting the humanities convention of close textual analysis where page numbers matter more than publication year.

In-text format: (Author page) — no comma between name and page number.
Example: The narrator’s unreliability signals a deeper collapse of Enlightenment certainty (Pynchon 52).

Works Cited entry (book):
Pynchon, Thomas. The Crying of Lot 49. Lippincott, 1966.

Key MLA rules for thesis writers:

• The bibliography is titled “Works Cited,” not “References” or “Bibliography.”
• Use a container system: a chapter inside a book, or an article inside a journal, is a “contained” work.
• Titles of short works (articles, poems, short stories) go in quotation marks; longer works are italicised.
• MLA does not prescribe specific header formatting — follow your department’s style sheet.

See our MLA format guide with full examples for every source type from books to TikTok videos.

Chicago — History, Arts, and Law

The Chicago Manual of Style, 17th edition, offers two distinct systems that serve different needs within the humanities and social sciences.

Notes-Bibliography (NB): Used in history, literature, arts, and theology. In-text citations appear as superscript footnote numbers, and the bibliography at the end lists full source details. This system allows discursive footnotes — a strength for history theses that need to contextualise sources or add commentary without interrupting the main text.

Author-Date: Used in social sciences (when not using APA), natural sciences, and some law programmes. Functions similarly to APA with parenthetical (Author Year) in-text citations and a reference list.

Notes-Bibliography footnote example:
¹ Antony Beevor, Stalingrad (London: Viking, 1998), 47.

Bibliography entry:
Beevor, Antony. Stalingrad. London: Viking, 1998.

When to use Chicago NB over MLA: If your thesis is primarily in history, art history, or philosophy and involves a large number of archival or primary sources, Chicago NB is almost always the better choice. The footnote system lets you cite primary documents, translations, and editorial notes without cluttering the main text.

Harvard — UK and Australian Universities

Unlike the styles above, Harvard is not governed by a single official manual. It is an author-date family of styles — similar in logic to APA — but each institution publishes its own Harvard guide with minor variations in punctuation, date placement, and abbreviation conventions. If your university says “use Harvard,” always download their specific Harvard guide from the library website rather than relying on a generic template.

In-text format: (Author Year, p. page) or (Author Year).
Example: Student engagement declines sharply after week six of online programmes (Smith 2022, p. 14).

Reference list entry (journal article):
Smith, J. (2022) ‘Online engagement dynamics in postgraduate education’, Higher Education Research, 45(3), pp. 10–28.

Harvard is the dominant default style at most UK universities for programmes that do not have a field-specific requirement. If you are at a UK institution studying anything outside medicine or engineering, Harvard is likely either mandated or strongly expected.

Vancouver — Medicine and Health Sciences

The Vancouver system, formally the International Committee of Medical Journal Editors (ICMJE) style, uses a numbered reference system where sources are cited as superscript or bracketed numbers in the order they first appear in the text. It is the standard for medicine, nursing, dentistry, physiotherapy, and public health theses.

In-text format: Numbered superscripts or square brackets in order of first appearance.
Example: Nicotine replacement therapy doubles the odds of successful cessation at 12 months.¹

Reference list entry (journal article):
1. Hartmann-Boyce J, Chepkin SC, Ye W, Bullen C, Lancaster T. Nicotine replacement therapy versus control for smoking cessation. Cochrane Database Syst Rev. 2018;5:CD000146.

Key Vancouver rules:

• References are numbered in order of citation, not alphabetically.
• The same source always keeps its first-assigned number, even if cited again later.
• Journal title abbreviations follow MEDLINE conventions.
• Only the first six authors are listed; for seven or more, use “et al.” after the sixth.

IEEE — Engineering and Computer Science

The Institute of Electrical and Electronics Engineers citation style is the standard for engineering, computer science, electronics, telecommunications, and related STEM fields. Like Vancouver, it uses a numbered reference system — but numbers appear in square brackets in the text and sources are listed in the order they were cited.

In-text format: [Number] in square brackets.
Example: Deep learning models have achieved near-human accuracy on ImageNet classification benchmarks [3].

Reference list entry (journal article):
[3] Y. LeCun, Y. Bengio, and G. Hinton, “Deep learning,” Nature, vol. 521, no. 7553, pp. 436–444, May 2015.

Key IEEE rules:

• Author first names are abbreviated to initials.
• Article titles appear in quotation marks; journal and conference titles are italicised.
• Volume, issue, page range, and month are all required for journal articles.
• Conference papers include the conference name, location, and year.

Read our full IEEE citation format guide for examples covering software, datasets, standards, and patents.

Style Comparison at a Glance

Automate Your Bibliography with Tesify

Manually formatting 80 references at 11 pm the night before submission is how citation errors happen. Tesify’s Auto Bibliography feature (product ID: cmmkk9c7j00017n9vp664a9cw) generates perfectly formatted reference lists in APA, MLA, Chicago, Harvard, Vancouver, and IEEE from a DOI, URL, ISBN, or plain-text source information. It handles edge cases — missing authors, organisational authors, preprints, software citations, and AI-generated sources — that trip up every generic citation tool.

You can switch between styles in one click if your supervisor changes their mind mid-thesis. Every generated reference is cross-checked against the official style manual rules and flagged if the source data is incomplete. See how it compares to the competition in our full citation generator comparison for 2026.

Frequently Asked Questions