Almost every Indian medical university asks for references in the Vancouver style, yet the reference list is one of the most common reasons a thesis comes back for corrections. Numbers out of sequence, a mix of full and abbreviated journal names, missing volume numbers, and twenty authors listed for one paper are all easy for an examiner to spot.
This guide explains how Vancouver referencing works in an MD, MS or DNB thesis: how in-text numbering is done, the exact format for journal articles, books, chapters, websites and theses, the et al. rule, where to find correct journal abbreviations, and how to let Zotero, Mendeley or EndNote do the formatting for you. It follows the conventions of the US National Library of Medicine (NLM) book Citing Medicine and the NLM sample references used with the ICMJE Recommendations. Your university’s own thesis guidelines always take priority.
1What Vancouver Style Is
Vancouver is a numbered citation system. Instead of writing the author’s name and year in the text, you place a number, and that number points to the full reference in a numbered list at the end of the thesis. The name comes from a 1978 meeting in Vancouver of medical journal editors, the group that later became the International Committee of Medical Journal Editors (ICMJE). Today the detailed formatting rules are maintained by NLM in Citing Medicine, which is freely available online on the NCBI Bookshelf.
There is no single “official” Vancouver template that every university uses. Small details such as square brackets versus superscripts, or how many authors to list, differ between institutions. Learn the core rules below, then match the details to your university’s dissertation guidelines and to recently accepted theses in your department.
2In-Text Citations: Numbering by First Appearance
The central rule: references are numbered consecutively in the order in which they are first cited in the text.
- The first source you cite in the Introduction is 1, the next new source is 2, and so on through every chapter.
- When you cite a source again later, reuse its original number. Do not give it a new number.
- Cite multiple sources together with commas, and use a hyphen or en dash for a continuous range: 3,7,12 or 4–8.
- References cited only in tables or figure legends are numbered according to where that table or figure is first mentioned in the text.
- Numbers can be shown as superscripts or in square brackets or parentheses. Use whichever your university specifies, and use it consistently.
When you mention an author by name, keep the number with the name: “Author et al. reported a similar association [14].” Use the first author’s surname only, followed by et al. when there are more than two authors.
Do not sort the Vancouver reference list alphabetically. It must run in citation order. If you move a paragraph from the Discussion into the Review of Literature late in writing, the numbering changes, which is the strongest argument for using a reference manager from day one.
3Reference Formats with Examples
The examples below use placeholders rather than real papers. Replace each placeholder with the details of your source, keeping the punctuation exactly as shown.
Journal article
Author AB, Author CD, Author EF. Title of the article in sentence case. J Abbrev. Year;Vol(Issue):Pages.
Points to note:
- Author names: surname, a space, then initials with no full stops or spaces between them (Author AB). Authors are separated by commas, and the list ends with a full stop.
- Article title in sentence case: capitalise only the first word, proper nouns and abbreviations.
- Journal title abbreviated as in the NLM Catalog, with no full stops in the abbreviation and no italics.
- No spaces in
Year;Vol(Issue):Pages. NLM style shortens the page range by dropping repeated digits (for example 123-9 rather than 123-129). Some universities prefer full page numbers; follow yours. - If you add a DOI, place it at the end:
... Year;Vol(Issue):Pages. doi:10.xxxx/xxxxx
Organisation as author
Name of Organisation. Title of report or article. J Abbrev. Year;Vol(Issue):Pages.
Book
Author AB, Author CD. Title of book. 5th ed. Place of publication: Publisher; Year.
Leave out the edition statement for a first edition. For an edited book, add “editors” after the names: Editor AB, Editor CD, editors. Title of book. ...
Chapter in an edited book
Author AB. Title of chapter. In: Editor CD, Editor EF, editors. Title of book. 3rd ed. Place of publication: Publisher; Year. p. 45-60.
This format is the one to use for most clinical textbooks, where each chapter has its own author. Cite the chapter author first, not the book editor.
Website or web page
Name of Organisation. Title of web page [Internet]. Place: Publisher; Year [updated Year Mon Day; cited Year Mon Day]. Available from: URL
The “cited” date is the date you accessed the page. Record it at the time you read the page; it is very hard to reconstruct later.
Thesis or dissertation
Author AB. Title of thesis [dissertation]. Place: Name of University; Year.
Citing Medicine uses “[dissertation]” for doctoral work and “[master’s thesis]” for master’s work. Some Indian universities prefer a description such as “[MD thesis]”; check your guidelines.
Online journal article ahead of print
Author AB, Author CD. Title of article. J Abbrev. Year Mon Day. doi:10.xxxx/xxxxx. [Epub ahead of print]
PubMed can do much of this for you. Open any article in PubMed and click “Cite”; the NLM format it shows follows these conventions. Check it against your university’s style rather than pasting it blindly. Our guide to searching PubMed shows where these options sit.
4The Et Al. Rule for Many Authors
The rule most widely used in medical theses comes from NLM’s sample references for the ICMJE Recommendations: list all authors when there are six or fewer; when there are more than six, list the first six followed by et al.
Author AB, Author CD, Author EF, Author GH, Author IJ, Author KL, et al. Title of article. J Abbrev. Year;Vol(Issue):Pages.
Be aware that this is not universal:
- Citing Medicine itself prefers listing all authors, and allows a limit (for example, the first three followed by et al.) when one is needed.
- Some Indian universities and departments ask for the first three authors followed by et al.
- Some ask for all authors to be listed.
Pick the rule your university specifies and apply it to every single reference. Mixed rules within one list are a common examiner comment.
5Journal Abbreviations from the NLM Catalog
Vancouver style uses standard abbreviated journal titles, not full titles and not abbreviations you invent. The authoritative source is the NLM Catalog (search “NLM Catalog” on the NCBI website). Search for the journal by its full name and use the “NLM Title Abbreviation” shown in the record.
A few real examples show the pattern, with no full stops:
| Full journal title | NLM abbreviation |
|---|---|
| The New England Journal of Medicine | N Engl J Med |
| The Indian Journal of Medical Research | Indian J Med Res |
| The Journal of the Association of Physicians of India | J Assoc Physicians India |
| The National Medical Journal of India | Natl Med J India |
Single-word journal titles such as Lancet or Pediatrics are not abbreviated. If a journal is not in the NLM Catalog, many universities accept the full title; ask your guide.
6Using Zotero, Mendeley or EndNote
Formatting 100 or more references by hand is slow and error-prone, and renumbering after edits is worse. A reference manager inserts citations into Word, numbers them in order of first appearance and builds the list automatically.
- Zotero (free): install the desktop app, the browser connector and the Word plugin. Save papers from PubMed with one click. In Word, open Zotero’s Document Preferences and choose a Vancouver style. If it is not listed, add it from the Zotero Style Repository through the app’s style settings.
- Mendeley (free): use Mendeley Reference Manager with the Mendeley Cite add-in for Word, and select a Vancouver citation style from the style list.
- EndNote (paid; many institutions provide it): use the Cite While You Write tools in Word and select the Vancouver output style.
Whichever you use, the software is only as good as the data in it. Before final submission, check every entry for missing issue numbers, author names in capitals, journal titles in full instead of abbreviated, and duplicates of the same paper.
Do not “unlink” or convert citations to plain text until the thesis is completely final. Once unlinked, the reference manager can no longer renumber them, and any late change means manual corrections throughout.
7Common Vancouver Mistakes in Theses
| Mistake | Correct approach |
|---|---|
| Reference list sorted alphabetically | Number in order of first citation in the text |
| Same source given two different numbers | Reuse the first number every time it is cited |
| Full stops in initials or journal abbreviations (A.B., J. Med.) | No full stops: Author AB, J Abbrev |
| Mixing full and abbreviated journal titles | Use NLM Catalog abbreviations throughout |
| Different et al. rules in different entries | Apply your university’s rule to every entry |
| Article titles in Title Case or all capitals | Sentence case for article titles |
| Missing volume, issue or pages | Complete every element; check PubMed for missing details |
| Citations in the text with no matching entry, or entries never cited | Cross-check text and list before submission |
| Citing a paper you only saw quoted in another thesis | Read and cite the original source |
| Websites without an access date | Add the [cited Year Mon Day] date |
Accurate referencing also matters for similarity checks: properly cited and paraphrased text is part of academic integrity, as explained in our post on plagiarism checks and similarity index. For how references fit into the chapter where you will use most of them, see how to write the Review of Literature.
8Getting Your References Right
A clean, consistent reference list tells examiners that the rest of the thesis was done with the same care. Set up a reference manager early, confirm your university’s exact rules, and check the final list line by line. If you would like help formatting or checking a reference list, or converting a thesis to your university’s Vancouver style, the PubMedico team can help; message us on WhatsApp at +91 78787 33004. For an overview of every thesis stage, read our step-by-step MD/DNB thesis guide.
❓ Frequently Asked Questions
Quick answers to common questions on this topic
NLM and ICMJE do not impose one rule for thesis writing, and practice differs between universities and journals. Some place the number before the punctuation mark, others after it. Check your university thesis guidelines or recently accepted theses in your department, pick one placement and use it consistently throughout every chapter.
Yes, both are accepted forms of Vancouver citation. Superscripts are common in journals, while square brackets or parentheses are common in theses because they are easier to read in typed text. Use the form your university specifies; if it does not specify, ask your guide and keep it consistent.
The best practice is to find and read the original source, then cite it directly. If the original is truly unavailable, cite the source you actually read and mention in the text that it quotes the original. Citing a paper you have not read risks copying errors in its details or interpretation.
Yes. Numbering runs continuously through the whole thesis in order of first citation. A study first cited in the Introduction keeps that number in the Review of Literature and Discussion. New studies cited for the first time in the Discussion get the next available numbers.
They are closely related. The ICMJE Recommendations point authors to NLM's sample references, and NLM's book Citing Medicine gives the detailed rules. Most reference managers label the resulting style 'Vancouver' or 'NLM'. Small differences exist between versions, so match your output to your university's own example references.
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