Complete Vancouver citation guide

The Vancouver system is the standard in health sciences. If you study Medicine, Nursing, Dentistry or related fields at UNAH, UNICAH or any Honduran university, you'll likely need this format. This guide covers everything you need to master Vancouver style: from the basic numbering logic to detailed examples for every source type, common pitfalls, and how it compares to other citation systems.

What is the Vancouver system

Vancouver is a numerical citation style created in 1978 by a group of biomedical journal editors who met in Vancouver, Canada. The group eventually became the International Committee of Medical Journal Editors (ICMJE), which still maintains the guidelines today. Since then, Vancouver has become the required format for most health science publications worldwide.

The core idea is simple: each source receives a number based on the order it first appears in the text. References at the end are listed in numerical order, not alphabetical. This makes it fundamentally different from APA, which uses an author-year system.

How the numbering system works

The backbone of Vancouver is consecutive numbering. Here's how it operates:

1. The first source you cite in your text gets number 1
2. The second source gets number 2, and so on
3. If you cite source 1 again in a later paragraph, you use the same number 1 — you don't assign a new one
4. Numbers are never duplicated for different sources and never skipped

This system has a practical advantage: readers can quickly see how many sources you used and the order in which you introduced them. It also keeps the text cleaner, without "(Lopez, 2024)" interruptions every few lines.

How to cite in the text

Citations are marked with numbers in parentheses or as superscript. The choice depends on what your university or target journal requires:

• Parentheses: "The study showed significant improvements (1)."
• Superscript: "The study showed significant improvements¹."

For multiple sources at the same point: (1,3,5) or (1-5) for consecutive ranges.

Key in-text citation rules

1. The first cited source receives number 1, the second number 2, and so on
2. If you cite a previously mentioned source, repeat the same number
3. Author surnames are not used in the text (unlike APA)
4. When using superscript, the number goes after the punctuation mark
5. For direct quotes, include the page number: (1, p. 45)
6. If you mention the author in the sentence, the number follows immediately: "According to Lopez (1), the results indicate..."

In-text citation examples

Situation	Correct example
Indirect citation	"Type 2 diabetes has increased by 40% in the last decade (1)."
Direct quote	"The results were statistically significant" (2, p. 87).
Multiple sources	"Several authors agree on this finding (3-5,8)."
Author mentioned	"According to Martinez (6), prevalence is higher in rural areas."
Same source again	"This data confirms the previous findings (1)." — same number

How to format the reference list

The reference list goes at the end of the document, ordered numerically (not alphabetically). Each entry corresponds to the number assigned in the text. Below are the formats for the most common source types.

Journal article (the most frequent)

Surname Initials. Article title. Abbreviated Journal Name. Year;Volume(Issue):Pages.

Example: Lopez RA, Martinez JC. Risk factors in type 2 diabetes. Rev Med Hondur. 2024;92(3):145-152.

Additional rules for journal articles:

• List up to 6 authors, separated by commas
• For more than 6 authors, list the first 6 followed by "et al."
• Journal names must be abbreviated according to the Index Medicus (NLM Catalog)
• No period after the journal abbreviation

Book

Surname Initials. Book title. Edition. City: Publisher; Year.

Example: Hernandez Sampieri R. Metodologia de la investigacion. 7th ed. Mexico City: McGraw-Hill; 2018.

Notes:

• The first edition is not indicated
• From the second edition onward, write "2nd ed.", "3rd ed.", etc.
• Multiple author rules are the same as for journal articles

Book chapter

Chapter Author Surname Initials. Chapter title. In: Editor Surname Initials, editor. Book title. Edition. City: Publisher; Year. p. Pages.

Example: Rosales F. Epidemiology of tropical diseases. In: Villanueva A, editor. Public health in Central America. 2nd ed. Tegucigalpa: Editorial Universitaria; 2023. p. 89-112.

Website

Author/Organization. Page title [Internet]. City: Publisher; Year [cited access date]. Available from: URL

Example: World Health Organization. Diabetes [Internet]. Geneva: WHO; 2023 [cited 2024 Mar 15]. Available from: https://www.who.int/news-room/fact-sheets/detail/diabetes

Thesis or dissertation

Surname Initials. Thesis title [dissertation]. City: University; Year.

Example: Fernandez PA. Prevalence of arterial hypertension in elderly adults in San Pedro Sula [dissertation]. Tegucigalpa: Universidad Nacional Autonoma de Honduras; 2023.

Conference paper

Surname Initials. Paper title. In: Conference title; Date; Location. City: Publisher; Year. p. Pages.

Example: Mejia R. Advances in rural telemedicine. In: Proceedings of the Central American Public Health Congress; 2024 May 10-12; San Pedro Sula. Tegucigalpa: UNAH; 2024. p. 34-38.

Legal document or regulation

Jurisdiction. Title of regulation. Official publication. Date of publication.

Example: Honduras. General Health Law. La Gaceta. 2005 Nov 14.

Comparison table: Vancouver vs APA vs Chicago

Criteria	Vancouver	APA 7	Chicago
Primary fields	Health sciences	Social sciences, education, psychology	Humanities, history, arts
Citation type	Numerical (1, 2, 3)	Author-year (Lopez, 2024)	Footnotes or author-date
Reference order	Numerical (order of appearance)	Alphabetical	Alphabetical or by note
Max authors listed	6 + et al.	20 + ... et al.	Varies by variant
Journal names	Abbreviated	Full	Full
Use of italics	Minimal	Book and journal titles	Book and journal titles
Complexity	Low	Medium	High

Which Honduran universities require Vancouver

Vancouver isn't universal across all programs. Here's a breakdown by university and faculty:

University	Programs using Vancouver	Programs using APA
UNAH	Medicine, Nursing, Dentistry, Microbiology, Pharmacy	Psychology, Sociology, Education, Social Work, Law
UNICAH	Medicine, Nursing, Nutrition	Law, Psychology, Business
UNITEC	Generally APA across all programs	Engineering, Business, Communications
CEUTEC	Rarely uses Vancouver	Most programs use APA
UPN	School health (specific cases)	Education programs (APA)
UTH	Specific cases in occupational health	Most programs use APA

Not sure which format you need? Each university has its own rules, and sometimes they vary by class or professor. At Folium Labs we know each institution's requirements. Get a free format review quote.

Common Vancouver mistakes

These are the mistakes we see most frequently in the papers we review:

1. Mixing Vancouver with APA in the same document — Surprisingly common, especially when copying references from different sources
2. Not abbreviating journal names correctly — You must use the official Index Medicus abbreviation
3. Forgetting the access date for electronic sources — It's mandatory for every online resource
4. Not maintaining consecutive numbering when adding new citations — If you remove a source, you must renumber everything
5. Placing numbers before the period in superscript — The number goes after the punctuation mark
6. Using "and" or "&" between authors — In Vancouver, authors are separated only by commas
7. Not listing all required authors — Up to 6 are listed in full; "et al." is only used after the sixth
8. Writing the full journal name — Vancouver requires abbreviations; writing "Revista Medica Hondureña" instead of "Rev Med Hondur" is an error

Step by step: how to apply Vancouver to your paper

If you've never used Vancouver before, follow these steps:

1. Number your sources as you cite them for the first time in the text
2. Keep a tracking sheet with the number and full source details
3. Verify journal abbreviations using the NLM Catalog (ncbi.nlm.nih.gov/nlmcatalog)
4. Format each reference according to its source type (article, book, website, etc.)
5. Check for consistency — every number in the text must have a matching reference
6. Use a reference manager to avoid manual errors

Useful tools

To manage your Vancouver references, consider these options:

1. Zotero (free) — Exports in Vancouver format, excellent for team collaboration
2. Mendeley (free) — Integrates with Word, a good choice if you already use it
3. EndNote (paid) — The most comprehensive option for health sciences, commonly used in research labs
4. Google Scholar — Not a manager per se, but the "Cite" option provides basic formatting for many sources

Practical tip

If you use Word, both Zotero and Mendeley have plugins that insert citations and generate the reference list automatically. This eliminates numbering errors and saves hours of manual work.

Frequently asked questions

If I remove a citation, do I need to renumber all the others? Yes. Vancouver requires consecutive numbering with no gaps. If you remove source 3, what was source 4 becomes 3, and so on. This is why it's best to finalize numbering as the very last step of your revision.

Can I use Vancouver and APA in the same paper? No. You must use a single citation system throughout the entire document. Mixing formats is one of the most penalized errors.

How do I cite a source that was already cited? Use the same number you assigned it the first time. No matter how many times you cite it, it always keeps the same number.

How many references should I have at minimum? It depends on the type of work: an undergraduate thesis typically requires 30-50 references; a scientific article needs 20-40; a monograph requires 15-25.

Format review is one of our most requested services. We apply Vancouver, APA 7, Chicago and institutional formats. Learn about our format services.