This section describes the numbered reference system and gives examples from one version of the system. Ask your instructor what specific style to use.
Documentation styles for chemistry, computer science, mathematics, physics, and medical sciences are summarized in James D. Lester, Writing Research Papers, 5th ed., pp. 231-237, available in the Writing Center.
Create in-text citations
When using numbered references, cite a source by using the number assigned to that source in the reference list.
Use the information below for guidelines on how to cite numbered references correctly in your text.
Number your citations
Depending upon the system used in your field, either:
- Arrange the sources you cite alphabetically and then number them; or
- Number the citations consecutively according to the first mention of each source in the text (using the same number for subsequent references to the same source).
Format your citations
- Place the number in parentheses or in square brackets; or
- Use a superscript (a number above the text line, as for a footnote).
Include a page number
Add a comma and the page number(s) of the source.
The method was described in 1979 (2, p. 885).
[The citation indicates that the method was described on page 885 of reference number 2 (Israel et al.) on the reference list in the Writing Center handout about numbered references entitled "The Reference List." Notice that the period for the sentence comes after the closing parenthesis.]
Make the citation part of your sentence
Place the number directly after the author's name or mention of the work :
The work of Nelkin and Pollack (6) supports this theory.
A 1979 study (4) showed. . . .
You can refer to a number of works within one pair of parentheses or brackets or in a series of superscript numbers:
Numerous studies (1, 3, 4, 8, 9) refer to . . .