Wilkes University

Vancouver Referencing Guide: In-text Citations

A guide to the Vancouver referencing style commonly used in the biomedical sciences

When to Cite

Provide documentation for a:

  • Direct quotation. If you use another person's words OR an illustration such as a graph, table or figure
  • Paraphrasing of a quotation, passage, or idea: if you render someone else's idea by using your own words
  • Summary of another's idea or research. if you use someone else's ideas, opinions, research that your readers might want to investigate
  • Specific reference to an obscure fact or figure: If you use information that might need confirmation

It is not necessary to cite "common knowledge," which is information that is not the creation of any one person or that can be confirmed in many places. Common knowledge includes facts, dates, information or concepts that are generally known to an educated public. Examples include the chemical structure of water, referring to to the Patient Protection and Affordable Care Act as Obamacare, and early penicilllin derived from mold. Nor is it necessary to cite common phrases or proverbs such as "To err is human," or "The early bird catches the worm." You may consider something "common knowledge" if you find the same information undocumented (uncredited) in multiple reliable sources.

In-text Citations in the Body of a Paper

In the Vancouver style, you assign a number to each reference within the text as you cite it.  The citations are identified by Arabic numbers in superscript.  The number must be used even if the author(s) is named in the text. 

            Example:  In his study, Babbott11 found that….

New sources are numbered consecutively as they occur in the text.  If a source is repeated, so is the number originally assigned to it. 

When multiple references are cited at the same place in the text, use commas without spaces to separate non-inclusive numbers.

            Example:  Multiple studies have indicated….1,3,9,16 

If multiple references cited at the same place in the text are inclusive, use a hyphen to join the first and last numbers.

            Example:  Multiple studies have indicated that….7-10

Placement of the citation numbers is generally at the end of the sentence, unless there are two individual sets of citations in each sentence.  Generally reference numbers should be placed outside of periods and commas, inside of colons and semicolons.

One citation or one set of citations in one sentence:

The design of the FHS Daily Trial has been described previously.16

We assessed infarct size by cMRI, which strongly correlates with subsequent mortality.4,20,21

Two individual citations or more than one set of citations in one sentence:

There have been efforts to replace mouse inoculation testing with in vitro tests, such as enzyme linked immunosorbent assays57, 60 or polymerase chain reaction20-22, however these remain experimental.

Lack of reimbursement remains the single greatest obstacle to more widespread adoption of collaborative care,98 and we must continue to develop better funding mechanisms to capture its added value.99,100

Block Quotations:

Quotes longer than 4 lines should be indented in a block, without quotation marks and in reduced type.

For example:

With the increased need to store data and information generated by big projects, computational solutions, such as cloud-based computing, have emerged. Cloud computing is the only storage model that can provide the elastic scale needed for DNA sequencing, whose rate of technology advancement could now exceed Moore's Law. Moore's law is the observation that, over the history of computing hardware, the number of transistors on integrated circuits and the speed of computers doubles approximately every 2 years. Although cloud solutions from different companies have been used, several challenges remain, particularly related to the security and privacy of personal medical and scientific data.1