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.
*This version is used, with slight variations, in many journals and in two books on scientific writing: Robert A. Day’s How to Write and Publish a Scientific Paper and F. Peter Woodford’s Scientific Writing for Graduate Students (both available in the Writing Center).
Create a reference list
List the works cited, with corresponding numbers, on a new page after the text, titled References. Although the sample list below is not arranged alphabetically, you should arrange your reference list in alphabetical order.
Check James D. Lester, Writing Research Papers, 5th ed., pp. 231-237 (available in the Writing Center) or the documentation manual for your field for arrangement and numbering of the list and for style and order of elements within each entry.
Use the table below for guidelines on how to format the entries in a numbered reference list.
Book (1): Single author
1. Zimmerman, B.K. 1984. Biofuture, confronting the genetic era. Plenum Press, New York.
Book (2): 2 authors
2. Nelkin, D., and M. Pollack. 1980. Problems and procedures in the regulation of technological risk. In R. Schwing and W. Albers (eds.), Societal risk management. p. 136-67. Plenum Press, New York.
Book (3): Editor in place of author
3. Milunsky, A., and G.J. Annas (eds.). 1976. Genetics and the law. Plenum Press, New York.
Book (4): 2nd or later edition
4. Burns, George W. 1980. The science of genetics: an introduction to heredity. 4th ed. Macmillan. New York.
Book (5): Volume in a multivolume work
5. Hotchkiss, R.D. 1980. Recombinant DNA research, vol. 5. NIH Publication No. 80-2130.
Book (6): Subtitled volume of multivolume work
6. Office of Technology Assessment, U.S. Congress. 1980. Energy for biological processes, vol. 2. Technical analysis. U.S. Government Printing Office, Washington, D.C.
Book (7): Article in edited collection
7. Nelkin, D., and M. Pollack. 1980. Problems and procedures in the regulation of technological risk. In R. Schwing and W. Albers (eds.), Societal risk management. p. 136-67. Plenum Press, New York.
Book (8): Corporate author
8. National Research Council. 1977. World food and nutrition study: the potential contributions of research. Author, Washington, D.C.
9. Office of Technology Assessment, U.S. Congress. 1980. Energy for biological processes, vol. 2. Technical analysis. U.S. Government Printing Office, Washington, D.C.
Journal Article (1): Single author
10. Myers, N. 1979. Conserving our global stock. Environment 21: 25-30.
Journal Article (2): More than 1 author
11. Israel, M.A., et al. 1979. Molecular cloning of polyoma virus DNA in escherichia coli: plasmid vector systems. Science 203: 883-887.
Journal Article (3): In edited collection
12. Nelkin, D., and M. Pollack. 1980. Problems and procedures in the regulation of technological risk. In R. Schwing and W. Albers (eds.), Societal risk management. p. 136-67. Plenum Press, New York.
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.
Example:
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 . . .
