Scientific Style and Format Citation Quick Guide

Scientific Style and Format presents three systems for referring to references (also known as citations) within the text of a journal article, book, or other scientific publication: 1) citation–sequence; 2) name–year; and 3) citation–name. These abbreviated references are called in-text references. They refer to a list of references at the end of the document.

The system of in-text references that you use will determine the order of references at the end of your document. These end references have essentially the same format in all three systems, except for the placement of the date of publication in the name–year system.

Though Scientific Style and Format now uses citation–sequence for its own references, each system is widely used in scientific publishing. Consult your publisher to determine which system you will need to follow.

Click on the tabs below for more information and to see some common examples of materials cited in each style, including examples of electronic sources. For numerous specific examples, see Chapter 29 of the 8th edition of Scientific Style and Format.

Citation—Sequence and Citation—Name


The following examples illustrate the name–year system. In this system (sometimes called the Harvard system), in-text references consist of the surname of the author or authors and the year of publication of the document. End references are unnumbered and appear in alphabetical order by author and year of publication, with multiple works by the same author listed in chronological order.

Each example of an end reference is accompanied here by an example of a corresponding in-text reference. For more details and many more examples, see Chapter 29 of Scientific Style and Format.


For the end reference, list authors in the order in which they appear in the original text. The year of publication follows the author list. Use periods to separate each element, including author(s), date of publication, article and journal title, and volume or issue information. Location (usually the page range for the article) is preceded by a colon.

Author(s). Date. Article title. Journal title. Volume(issue):location.

Journal titles are generally abbreviated according to the List of Title Word Abbreviations maintained by the ISSN International Centre. See Appendix 29.1 in Scientific Style and Format for more information.

For the in-text reference, use parentheses and list author(s) by surname followed by year of publication.

(Author(s) Year)

For articles with 2 authors, names are separated by a comma in the end reference but by “and” in the in-text reference.

Mazan MR, Hoffman AM. 2001. Effects of aerosolized albuterol on physiologic responses to exercise in standardbreds. Am J Vet Res. 62(11):1812–1817.

(Mazan and Hoffman 2001)

For articles with 3 to 10 authors, list all authors in the end reference; in the in-text reference, list only the first, followed by “et al.”

Smart N, Fang ZY, Marwick TH. 2003. A practical guide to exercise training for heart failure patients. J Card Fail. 9(1):49–58.

(Smart et al. 2003)

For articles with more than 10 authors, list the first 10 in the end reference, followed by “et al.”

Pizzi C, Caraglia M, Cianciulli M, Fabbrocini A, Libroia A, Matano E, Contegiacomo A, Del Prete S, Abbruzzese A, Martignetti A, et al. 2002. Low-dose recombinant IL-2 induces psychological changes: monitoring by Minnesota Multiphasic Personality Inventory (MMPI). Anticancer Res. 22(2A):727–732.

(Pizzi et al. 2002)

Volume with no issue or other subdivision

Laskowski DA. 2002. Physical and chemical properties of pyrethroids. Rev Environ Contam Toxicol. 174:49–170.

(Laskowski 2002)

Volume with issue and supplement

Gardos G, Cole JO, Haskell D, Marby D, Paine SS, Moore P. 1988. The natural history of tardive dyskinesia. J Clin Pharmacol. 8(4 Suppl):31S–37S.

(Gardos et al. 1988)

Volume with supplement but no issue

Heemskerk J, Tobin AJ, Ravina B. 2002. From chemical to drug: neurodegeneration drug screening and the ethics of clinical trials. Nat Neurosci. 5 Suppl:1027–1029.

(Heemskerk et al. 2002)

Multiple issue numbers

Ramstrom O, Bunyapaiboonsri T, Lohmann S, Lehn JM. 2002. Chemical biology of dynamic combinatorial libraries. Biochim Biophys Acta. 1572(2–3):178–186.

(Ramstrom et al. 2002)

Issue with no volume

Sabatier R. 1995. Reorienting health and social services. AIDS STD Health Promot Exch. (4):1–3.

(Sabatier 1995)


In the end reference, separate information about author(s), date, title, edition, and publication by periods. The basic format is as follows:

Author(s). Date. Title. Edition. Place of publication: publisher. Extent. Notes.

Extent can include information about pagination or number of volumes and is considered optional. Notes can include information of interest to the reader, such as language of publication other than English; such notes are optional. Essential notes provide information about location, such as a URL for online works. See Chapter 29 for more information.

For books with 2 authors, names are separated by a comma in the end reference but by “and” in the in-text reference.

Leboffe MJ, Pierce BE. 2010. Microbiology: laboratory theory and application. Englewood (CO): Morton Publishing Company.

(Leboffe and Pierce 2010)

For books with 3 to 10 authors, list all authors in the end reference; in the in-text reference, list only the first, followed by “et al.”

Ferrozzi F, Garlaschi G, Bova D. 2000. CT of metastases. New York (NY): Springer.

(Ferrozzi et al. 2000)

For books with more than 10 authors, list the first 10 in the end reference, followed by “et al.”

Wenger NK, Sivarajan Froelicher E, Smith LK, Ades PA, Berra K, Blumenthal JA, Certo CME, Dattilo AM, Davis D, DeBusk RF, et al. 1995. Cardiac rehabilitation. Rockville (MD): Agency for Health Care Policy and Research (US).

(Wenger et al. 1995)

Organization as author

[ALSG] Advanced Life Support Group. 2001. Acute medical emergencies: the practical approach. London (England): BMJ Books.

(ALSG 2001)

Author(s) plus editor(s) or translator(s)

Klarsfeld A, Revah F. 2003. The biology of death: origins of mortality. Brady L, translator. Ithaca (NY): Cornell University Press.

Luzikov VN. 1985. Mitochondrial biogenesis and breakdown. Galkin AV, translator; Roodyn DB, editor. New York (NY): Consultants Bureau.

(Klarsfeld and Revah 2003)

(Luzikov 1985)

Chapter or other part of a book, same author(s)

Gawande A. 2010. The checklist manifesto: how to get things right. New York (NY): Metropolitan Books. Chapter 3, The end of the master builder; p. 48–71.

(Gawande 2010)

Chapter or other part of a book, different authors

Rapley R. 2010. Recombinant DNA and genetic analysis. In: Wilson K, Walker J, editors. Principles and techniques of biochemistry and molecular biology. 7th ed. New York (NY): Cambridge University Press. p. 195–262.

(Rapley 2010)

Multivolume work as a whole

Alkire LG, editor. 2006. Periodical title abbreviations. 16th ed. Detroit (MI): Thompson Gale. 2 vol. Vol. 1, By abbreviation; vol. 2, By title.

(Alkire 2006)

Dissertations and Theses

Lutz M. 1989. 1903: American nervousness and the economy of cultural change [dissertation]. [Stanford (CA)]: Stanford University.

(Lutz 1989)


Blanco EE, Meade JC, Richards WD, inventors; Ophthalmic Ventures, assignee. 1990 Nov 13. Surgical stapling system. United States patent US 4,969,591.

(Blanco et al. 1990)


Weiss R. 2003 Apr 11. Study shows problems in cloning people: researchers find replicating primates will be harder than other mammals. Washington Post (Home Ed.). Sect. A:12 (col. 1).

(Weiss 2003)


Indicate a copyright date with a lowercase “c”.

Johnson D, editor. c2002. Surgical techniques in orthopaedics: anterior cruciate ligament reconstruction [DVD]. Rosemont (IL): American Academy of Orthopaedic Surgeons. 1 DVD.

(Johnson c2002)

Websites and Other Online Formats

References to websites and other online formats follow the same general principles as for printed references, with the addition of a date of update/revision (if available) along with an access date and a URL.


Format for end reference:

Title of Homepage. Date of publication. Edition. Place of publication: publisher; [date updated; date accessed]. Notes.

If no date of publication can be determined, use a copyright date (if available), preceded by “c”. Include the URL in the notes.

APSnet: plant pathology online. c1994–2005. St Paul (MN): American Phytopathological Association; [accessed 2005 Jun 20].

For the in-text reference, include only the first word or two of the title (enough to distinguish it from other titles in the reference list), followed by an ellipsis.

(APSnet . . . c1994–2005)

Online journal article

Format for end reference:

Author(s) of article. Date of publication. Title of article. Title of journal (edition). [date updated; date accessed];Volume(issue):location. Notes.

A DOI (Digital Object Identifier) may be included in the notes in addition to a URL, if available:

Savage E, Ramsay M, White J, Beard S, Lawson H, Hunjan R, Brown D. 2005. Mumps outbreaks across England and Wales in 2004: observational study. BMJ. [accessed 2005 May 31];330(7500):1119–1120. doi:10.1136/bmj.330.7500.1119.

(Savage et al. 2005)


Format for end reference:

Author(s). Date of publication. Title of book. Edition. Place of publication: publisher; [date updated; date accessed]. Notes.


Brogden KA, Guthmille JM, editors. 2002. Polymicrobial diseases. Washington (DC): ASM Press; [accessed February 28, 2014].

(Brogden and Guthmille 2002)


Format for end reference:

Author’s name. Date of publication. Title of post [descriptive word]. Title of blog. [accessed date]. URL.


Fogarty M. 2012 Aug 14. Formatting titles on Twitter and Facebook [blog]. Grammar Girl: Quick and Dirty Tips for Better Writing. [accessed 2012 Oct 19].

(Fogarty 2012)

Forthcoming or Unpublished Material

Not all forthcoming or unpublished sources are suitable for inclusion in reference lists. Check with your publisher if in doubt.

Forthcoming journal article or book

Journal article:

Farley T, Galves A, Dickinson LM, Perez MJ. Forthcoming 2005 Jul. Stress, coping, and health: a comparison of Mexican immigrants, Mexican-Americans, and non-Hispanic whites. J Immigr Health.

(Farley et al. 2005)


Goldstein DS. Forthcoming 2006. Adrenaline and the inner world: an introduction to scientific integrative medicine. Baltimore (MD): Johns Hopkins University Press.

(Goldstein 2006)

Paper or poster presented at meeting

Unpublished presentations are cited as follows:

Antani S, Long LR, Thoma GR, Lee DJ. 2003. Anatomical shape representation in spine x-ray images. Paper presented at: VIIP 2003. Proceedings of the 3rd IASTED International Conference on Visualization, Imaging and Image Processing; Benalmadena, Spain.

Charles L, Gordner R. 2005. Analysis of MedlinePlus en Español customer service requests. Poster session presented at: Futuro magnifico! Celebrating our diversity. MLA ’05: Medical Library Association Annual Meeting; San Antonio, TX.

(Atani et al. 2003)

(Charles and Gordner 2005)

References to published presentations are cited much like contributions to books, with the addition of information about the date and place of the conference. See Chapter 29 for more information.

Personal communication

References to personal communication are placed in running text rather than as formal end references. Permission is usually required and should be acknowledged in an “Acknowledgment” or “Notes” section at the end of the document.

. . . and most of these meningiomas proved to be inoperable (2003 letter from RS Grant to me; unreferenced, see “Notes”) while a few were not.