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Research Guides

Eastern Washington University Libraries


Examples of Citation Styles for the Sciences

There is no one set citation style in the sciences. Each journal may have a slightly different method of citing sources. Please consult with your professor on what exact style to follow. I am happy to help look over your paper and help with citing your sources.

Citing in the Geological Society of America (GSA) Style

GSA Style is the citation standard created by the Geological Society of America and is commonly used in the field of geology.

A GSA citation consists of two parts:

In-text citations: Every time you present information that you have obtained from another source, you must create an in-text citation for it. GSA Style does not use footnotes. Avoid using direct quotes and instead, summarize in your own words the ideas or facts that come from a source. Summaries need to include in-text citations.
References Cited: At the end of your literature review, you should have a reference list that will include all the sources that were cited in your paper.
The content of citations will vary depending on the source, but the following rules apply to all citations:

  • List references alphabetically by author's surname.
  • List authors by full last name and initials for first and (if applicable) middle names.
  •  If a source's DOI (digital object identifier) is available, you should include it at the end of the citation. (This is only applicable to online sources, not print sources).

The first line of each citation should be aligned with the left margin. The second and subsequent lines of each citation should be indented by 0.5 inches to create a hanging indent.

In-Text Citations

When you present information that comes from another source, you should create an in-text citation that includes both the author's last name and the four digit year of publication. You can do this in one of two ways:

  • Mention the author's last name in the sentence where you are presenting their findings, followed by the year in parentheses. 
    • Example: Smith (2011) found evidence that suggests that the Ramapo Fault has the potential to produce a major earthquake.
  • At the end of the sentence, include both the author's last name and year of publication, separated by a comma.
    • Example: Evidence suggests that the Ramapo Fault has the potential to produce a major earthquake (Smith, 2011).
Citing Multiple Authors
  • Two authors: Include the last names of both authors either in the sentence or in parentheses.
    • Examples:
      • Brown and Matthews (2015) suggest that the Ramapo Fault will cause a major earthquake.
      • It has been suggested that the Ramapo Fault will cause a major earthquake (Brown and Matthews, 2015).
  • Three to five authors: Include the last name of each author the first time the source is cited in your paper. For each in-text citation of the source after that, list only the first author followed by et al.
    • Examples:
      • First citation of source: It has been suggested that the Ramapo Fault will cause a major earthquake (Brown, Matthews, and Smith, 2015).
      • Later citations of same source: It has been suggested that the Ramapo Fault will cause a major earthquake (Brown et al., 2015).
  • Six authors or more: For every in-text citation, list the last name of the author followed by et al.
    • Example:
      • It has been suggested that the Ramapo Fault will cause a major earthquake (Barnes et al., 2013).

References Cited


Author(s), Year of publication, Title, Source, volume (if applicable), Pages.


Sears, J.W., 2012, Making Nuna and breaking Rodinia: Implications of Siberia-Laurentia connections for supercontinent cycles:

Geological Society of America Abstracts with Programs, v. 44, no. 7, p. 378.

Articles (articles in academic journals, newspapers, magazines)

Author(s), Year of Publication, Title: Subtitle (if applicable): Publication, Volume number, Page numbers, doi (if applicable).


Coogan, L.A., and Hinton, R.W., 2006, Do the trace element compositions of detrital zircons require Hadean continental crust?:

Geology, v. 34, p. 633–636, doi:10.1130/G22737.1.

Books (books, pamphlets, and multi-volume publications such as encyclopedias)

Author(s), Year of Publication, Title: Place of publication, Publisher, Number of pages.


Allmendinger, R.W., Cardozo, N., and Fisher, D., 2011, Structural Geology Algorithms: Vectors and Tensors in Structural Geology:

New York, Cambridge University Press, 304 p.

Chapters in a Book or Papers in a Multi-author Volume

Author(s), Year of Publication, Title of chapter, in Author(s)/editor(s) of full volume, Title, Place of publication (if available), Publisher (if available), Volume (if available), Pages.


Sawyer, D.S., Buffler, R.T., and Pilger, R.H., 1991, The crust under the Gulf of Mexico basin, in Salvador, A., ed.,

The Gulf of Mexico Basin: Boulder, Colorado, Geological Society of America, Geology of North America, v. J, p. 53–72.

Government Publications

Author(s), Year of publication, Title: Publisher, Volume (if applicable), Pages.


Hay, R.L., 1963, Stratigraphy and zeolitic diagenesis of the John Day Formation of Oregon: University of California Publications in

Geological Sciences, v. 42, p. 199–262.


Author(s), Year of publication, Title: Publisher, Series number (if available), Scale (if available), Number of sheets (if available), Number of text pages (if applicable).


Ernst, W.G., 1993, Geology of the Pacheco Pass quadrangle, central California Coast Ranges: Geological Society of America

Map and Chart Series MCH078, scale 1:24 000, 1 sheet, 12 p. text.

Symposiums and Conferences

Author(s), Year, Title, in Title of proceedings, Month and year of conference (include this only if year of conference differs from publication year): Place of publication: Publisher, Pages


Baar, C., 1972, Creep measured in deep potash mines vs. theoretical predictions, in Proceedings, Canadian Rock Mechanics

Symposium, 7th, Edmonton: Ottawa, Canada Department of Energy, Mines and Resources, p. 23–77.


Author, Year of publication, Title of webpage: URL (Month and year that site was accessed).


Scotese, C.R., 2003, PALEOMAP Project: (accessed August 2019).


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