Vancouver Reference Style: NLM and ICMJE Rules for Authors, Dates, Pages and Examples

Vancouver style is the numbered citation system used by most journals in medicine, nursing and public health. The name comes from a 1978 meeting of medical journal editors in Vancouver, the group that became the International Committee of Medical Journal Editors (ICMJE). The ICMJE Recommendations say references "should follow the standards summarized in the NLM's Sample References webpage and detailed in the NLM's Citing Medicine, 2nd edition." In practice, "Vancouver" means the US National Library of Medicine's Citing Medicine plus the ICMJE sample references.

This guide was checked against the references section of the ICMJE Recommendations, NLM's sample references page (last reviewed June 2, 2026), and the journals chapter (updated May 18, 2018) and books chapter of Citing Medicine, 2nd edition. The boxed examples are quoted from those sources.

1. In-text citations

• Number sources consecutively in the order they are first mentioned; the list follows the same order.
• Reuse the original number when you cite a source again.
• The ICMJE asks for Arabic numerals in parentheses in text, tables and legends: (1), (2,3).
• Real journals choose between (1), [1] and superscript¹, and they differ on compressing runs such as (1-3). Follow the journal's instructions.

The in-text citation generator shows both the bracketed and the superscript form.

2. Authors

Name format: Smith AB

Citing Medicine sets these rules:

• Surname first, followed by up to two initials for given and middle names.
• No periods and no spaces in the initials: Smith AB, not Smith, A. B.
• Separate authors with a comma and a space; never use "and" or "&".
• End the author group with a period.

Korean authors follow the same pattern with romanized names, as in this example from Citing Medicine:

Jun BC, Song SW, Park CS, Lee DH, Cho KJ, Cho JH. The analysis of maxillary sinus aeration according to aging process: volume assessment by 3-dimensional reconstruction by high-resolutional CT scanning. Otolaryngol Head Neck Surg. 2005 Mar;132(3):429-34.

How many authors: NLM principle vs. ICMJE practice

Many medical journals follow the ICMJE sample and list six authors before adding et al.; this site's generator does the same. If your journal wants three or all, adjust. See the et al. rules guide for other styles.

Rose ME, Huerbin MB, Melick J, Marion DW, Palmer AM, Schiding JK, et al. Regulation of interstitial excitatory amino acid concentrations after cortical contusion injury. Brain Res. 2002;935(1-2):40-6.

3. Date, volume, issue and pages: 2005 Mar;132(3):429-34

• Dates run year month day. Months are the first three letters of the English name with no period (Jan, Feb, Mar ... Sep ... Dec): 2002 Jul 25.
• Then a semicolon, the volume, the issue in parentheses, a colon and the pages, with no spaces: 2002 Jul 25;347(4):284-7.
• Do not repeat leading digits in page ranges. Citing Medicine's own example: 123-125 becomes 123-5. Ranges with letters, such as 124A-126A, stay as they are, and supplement pages put the letter first: S10-8.

4. Journal title abbreviations

Use the NLM (MEDLINE) abbreviation. The ICMJE points authors to the NLM Catalog (www.ncbi.nlm.nih.gov/nlmcatalog/journals).

• No periods: N Engl J Med, Arch Neurol, Otolaryngol Head Neck Surg.
• Drop articles, conjunctions and prepositions.
• Use the title in force when the article appeared. Citing Medicine notes that the British Medical Journal became BMJ in 1988, so earlier articles are cited as Br Med J.

Do not invent abbreviations. Look the journal up in the NLM Catalog and copy its "NLM Title Abbreviation". Journals outside MEDLINE may not have one.

5. Titles and language

• Capitalize only the first word, proper nouns and acronyms in article titles.
• Translate non-English titles into English in square brackets and give the language at the end (for example, "Korean."). The book examples in Citing Medicine end with "Spanish." or "Italian." in the same way.
• Journal and book titles are not italicized.

6. Missing publication details

Books and reports use "Place: Publisher; year." Citing Medicine adds US state codes in parentheses, as in Bethesda (MD); the ICMJE samples sometimes drop them (St. Louis: Mosby). When information cannot be found:

7. Official examples by type (ICMJE samples)

Journal article

Halpern SD, Ubel PA, Caplan AL. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002 Jul 25;347(4):284-7.

Book

Murray PR, Rosenthal KS, Kobayashi GS, Pfaller MA. Medical microbiology. 4th ed. St. Louis: Mosby; 2002.

Chapter in a book

Meltzer PS, Kallioniemi A, Trent JM. Chromosome alterations in human solid tumors. In: Vogelstein B, Kinzler KW, editors. The genetic basis of human cancer. New York: McGraw-Hill; 2002. p. 93-113.

Dissertation

Borkowski MM. Infant sleep and feeding: a telephone survey of Hispanic Americans [dissertation]. Mount Pleasant (MI): Central Michigan University; 2002.

Report

Yen GG (Oklahoma State University, School of Electrical and Computer Engineering, Stillwater, OK). Health monitoring on vibration signatures. Final report. Arlington (VA): Air Force Office of Scientific Research (US), Air Force Research Laboratory; 2002 Feb. Report No.: AFRLSRBLTR020123. Contract No.: F496209810049.

Newspaper article

Tynan T. Medical improvements lower homicide rate: study sees drop in assault rate. The Washington Post. 2002 Aug 12;Sect. A:2 (col. 4).

Conference paper

Christensen S, Oppacher F. An analysis of Koza's computational effort statistic for genetic programming. In: Foster JA, Lutton E, Miller J, Ryan C, Tettamanzi AG, editors. Genetic programming. EuroGP 2002: Proceedings of the 5th European Conference on Genetic Programming; 2002 Apr 3-5; Kinsdale, Ireland. Berlin: Springer; 2002. p. 182-91.

Website

Online sources carry the medium [Internet], the date you checked [cited year month day], and Available from: before the address. An update date, if shown, goes in [updated ...] before the cited date.

eatright.org [Internet]. Chicago: Academy of Nutrition and Dietetics; c2016 [cited 2016 Dec 27]. Available from: https://www.eatright.org/.

For online journal articles, [Internet] follows the journal title and [cited ...] follows the date. Many journals also require a DOI at the end; check the required format. See the DOI and URL guide.

8. Korean medical journals

Many Korean medical and nursing journals state that they follow the ICMJE Recommendations and Vancouver style, but check these details in the instructions for authors:

• Author limit: three, six, or all
• Number style: (1), [1] or superscript, and whether runs are compressed
• Korean-language sources: translated into English with "Korean." at the end, or kept in Hangul with full names
• DOI: required or not, and in which form

9. Common mistakes

1. Periods in initials (Smith A.B.). Write Smith AB.
2. "and" between authors.
3. Spelled-out or dotted months (March, Mar.). Write Mar.
4. Spaces in the source block (2002; 347 (4): 284-7).
5. Unabbreviated page ranges (284-287 instead of 284-7).
6. Full or dotted journal titles (N. Engl. J. Med.).
7. Missing [cited ...] for web sources.

Before submitting, confirm that numbering follows first mention, journal titles match the NLM Catalog, and the author limit matches the journal. The reference generator produces a numbered Vancouver list from your entries.

Examples by source type — Vancouver (NLM/ICMJE)

These examples are generated by this site's formatting engine from fictional sample data (not real publications).

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