Vancouver In-Text Citation: Rules and Examples

Vancouver is the numbered citation style used across medicine, nursing and the health sciences. The name comes from a 1978 meeting of medical journal editors in Vancouver, Canada. Today the International Committee of Medical Journal Editors (ICMJE) sets the basic rule, and the National Library of Medicine's Citing Medicine gives the detailed format of each reference.

Instead of an author and year, a Vancouver in-text citation is just a number. The reader finds the full source by looking up that number in the reference list at the end of your paper. The ICMJE recommendations put it simply: references "should be numbered consecutively in the order in which they are first mentioned in the text."

The 7 rules at a glance

1. Number sources in the order you first cite them, not alphabetically.
2. Use one number format throughout: round brackets, square brackets or superscript.
3. Give a repeated source the same number every time.
4. Separate several numbers with commas and join a run of three or more with a hyphen.
5. Put the number next to the author's name when you name the author in your sentence.
6. Add a page number when you quote, in the form your school uses.
7. Make every number match exactly one entry in the reference list.

Let the tool keep count

The Vancouver citation generator embedded above builds the numbered list for you. Paste a DOI, PubMed link, URL or ISBN, check the fields, and add sources in the order you cite them so the numbers line up with your text. It prints in-text numbers in round brackets, such as (1).

Students often ask which Vancouver style in-text citation format is correct. The honest answer is that all three are used. ICMJE asks for "Arabic numerals in parentheses," so many medical journals print (1). Many university library guides prefer superscript numbers. Monash University's guide, for example, uses superscript and accepts round or square brackets if your instructor prefers them, while the University of Queensland's guide uses superscript with no brackets.

Which one to choose

Your syllabus, your instructor or your target journal decides. If nothing is specified, round brackets are a safe choice because they match ICMJE and are easy to type.

Stay consistent

Whatever you choose, don't mix formats within one Vancouver in-text citation style. A paper with (1) on page 2 and a superscript³ on page 5 looks careless. If you switch formats late, use find and replace to fix every number at once.

Put the citation right after the fact it supports, not at the end of a long paragraph. If a sentence draws on two sources for two different points, cite each one where its point ends. Placement against punctuation depends on the format you use, so check the table and then your school's guide.

Quotation marks and parentheses

Monash University's guide places superscript numbers outside quotation marks and closing parentheses. With round or square brackets, most writers put the citation right after the closing quotation mark and before the period: Watson and Crick described "two helical chains each coiled round the same axis" (1 p. 737).

The number follows the order of first citation. It has nothing to do with the author's name, the year or the type of source. If your first sentence cites a 2009 WHO report, the WHO report is 1, even though "World Health Organization" would come last alphabetically.

A repeated source keeps its number

When you cite the same source again, reuse its original number. The University of Queensland guide states it directly: "If the source is referred to again, the same reference number is reused." So if Watson and Crick are source 1 and you cite them again on page 6, they're still (1), even if you've cited sources 2 to 12 in between.

Several works by one author

In a Vancouver in-text citation, each separate work gets its own number. If you cite two different articles by the same research group, they get two numbers, such as (3) and (7), in the order you first cite each.

When one statement draws on several sources, put all their numbers in one Vancouver in-text citation. A Vancouver in-text citation for multiple sources follows two simple rules.

Separate numbers with commas

Use commas between numbers that aren't consecutive: (1,3) or (2,5,8). Most library guides, including Queensland's, leave out the spaces: (1,3) rather than (1, 3). Some instructors accept either.

Join a run with a hyphen

For three or more numbers in a row, give the first and last joined by a hyphen: (4-6) instead of (4,5,6). The Queensland guide adds a useful rule: "Do not use a hyphen if there are no citation numbers in between," so two consecutive sources are written (2,3), not (2-3).

Mixing both

You can combine the two: (1,4-6,9) cites sources 1, 4, 5, 6 and 9. In superscript, the same citation is written ¹˒⁴⁻⁶˒⁹, all raised. Keep the numbers in ascending order inside the brackets.

In a Vancouver style in-text citation, sometimes you want the author to be part of your sentence, for example when you compare two studies. You can name the author in the text and still give the number. Library guides call this an author-prominent citation; the alternative, with only the number, is information-prominent.

One, two, or three or more authors

• One author: Borkowski (7) surveyed Hispanic American parents about infant sleep.
• Two authors: Watson and Crick (1) proposed a double helix.
• Three or more authors: Polack et al. (2) reported 95% efficacy.

The number goes right after the name, not at the end of the sentence. Monash and Queensland both use "and" for two authors and "et al." for three or more.

Vancouver doesn't require page numbers for paraphrases, because the reference list already gives the page range of an article or chapter. Add a page when you quote directly, or when you want to send the reader to one spot in a long book or report.

Forms you'll see

The format of a page number varies by school more than any other part of a Vancouver in-text reference. Common forms include:

• Round brackets: (6 p. 12) or (6, p. 12)
• Square brackets: [6 p. 12]
• Superscript: ⁶⁽ᵖ¹²⁾, with the page in parentheses after the number
• More than one page: (3 pp. 45-7)

Monash's guide writes "p" for one page and "pp" for several, in brackets after the number. The page numbers here are illustrative; take the real page from the source you quote.

Tables and figures use the same Vancouver in-text citation numbers as your text. If a table reports data from source 4, cite (4) in the table title, a column heading or the note under the table.

The ICMJE rule for numbering

A source can appear for the first time in a table or figure legend. ICMJE says such references should be numbered in the sequence set by the first time you mention that table or figure in the text. So if your text first mentions Table 1 right after citing source 5, a new source that appears only in Table 1 becomes 6.

Every Vancouver in-text citation points to one entry in the list at the end, titled References. The list is numbered in the same order as your citations: entry 1 is the first source you cited, entry 2 the next new one, and so on. It's never alphabetized.

What each entry looks like

A journal article entry gives the authors as last name and initials, the article title, the abbreviated journal name, the date, volume, issue and pages: "1. Watson JD, Crick FHC. Molecular structure of nucleic acids: a structure for deoxyribose nucleic acid. Nature. 1953 Apr 25;171(4356):737–8." Our Vancouver referencing examples guide has worked entries for books, chapters, websites, WHO and CDC reports, theses and conference papers, plus a full sample list.

Here's an example of Vancouver in-text citation in a short passage from an invented nursing student's paper, using round brackets. The numbers refer to the sample list in our Vancouver referencing examples guide.

The discovery of the double helix explained how genetic information is copied (1). In a trial of more than 40,000 participants, Polack et al. (2) found the BNT162b2 vaccine 95% effective. Both findings now appear in standard medical microbiology textbooks (3) and in reviews of cancer genetics (4). Watson and Crick (1) could not have predicted that reach.

What to notice

• The numbers run 1, 2, 3, 4 in the order each source first appears.
• Source 1 comes back in the last sentence with its original number.
• The author-prominent citations put the number right after the names.
• Sources 3 and 4 could also be cited together as (3,4) if they supported the same clause.

The most common slip in a Vancouver in-text citation is breaking that order: numbers must follow the order sources first appear on the page, not the order you found them.

If you've used other styles, in-text referencing in Vancouver will feel closest to IEEE, which also numbers sources in order of first citation.

Where to learn the others

The IEEE reference format guide covers bracketed numbers in engineering, the APA format guidelines guide covers author-date citations, and the MLA in-text citation guide covers author-page citations. If your instructor wants AMA style, which also uses superscript numbers in order of citation, the AMA citation generator handles that version.

These are the errors instructors mark most often in Vancouver style citation in text, with the fix for each.

There's no single Vancouver citation style manual for in-text citations. Two sources set the core rules, and university guides fill in the details.

ICMJE and NLM

The ICMJE Recommendations set numbering in order of first mention and Arabic numerals in parentheses. The National Library of Medicine's Citing Medicine, 2nd edition, is the full manual for formatting the references themselves, and its journal article chapter gives the pattern most of your entries will follow.

University library guides

Details such as superscript placement and page number format come from library guides, which differ slightly. Monash University's Vancouver guide is one of the clearest. When your school publishes its own guide, it overrides any general advice, including this page.

Next steps

When your citations are in place, let the Vancouver reference generator format the list, then compare it with the worked entries in our Vancouver referencing examples guide. Every guide we publish is listed on the student writing guides page.