How to Give Credit to Sources When Writing a Research Paper

When writing a research paper, finding and citing appropriate sources are the most important aspects of backing up your thesis. Proper sourcing can make the difference between strong and weak arguments in your paper. The two most commonly used writing and citation styles in research writing are the American Psychological Association (APA) and Modern Language Association (MLA) guidelines. While APA style is most commonly used to cite sources for research papers within the social sciences, MLA is more often used for liberal arts and humanities work.

APA Style

Cite sources on the reference page of your research paper by organizing sources alphabetically by the authors' last names. Each source should be cited beginning with the author's name, listed last name first, followed by the initials of the first name. Any additional authors for the same source should be added after a comma. Do not list more than six authors for a single source. For sources with seven or more authors, use ellipses after the sixth author's name.


Miller, F. H., Choi, M. J., Angeli, L. L., Harland, A. A., Stamos, J. A., Thomas, S. T., . . .

   Rubin, L. H. (2009). Web site usability for the blind and low-vision user. Technical

   Communication, 57, 323-335.

Begin the second line of your reference with a one-half inch indent from the left margin. Place the publication date of your source in parenthesis, followed by a period. Follow with the name of the article cited, followed by a period. Next, write the title of the publication where you found the source in italics, followed by a comma, followed by the issue number of the periodical or journal, also in italics. Place a comma after the issue number and list the pages where the article was found within the publication.


Harlow, H. F. (1983). Fundamentals for preparing psychology journal articles. Journal of

     Comparative and Physiological Psychology, 55, 893-896.

Cite sources in text by using the name of the first author listed in the source, followed by the publication date in parenthesis. You may begin your citation by referencing your source in the sentence, with the publication date in parenthesis, followed by the page number in parenthesis at the end of the sentence. If you use the title of a source within your paper, capitalize all words that are four letters or longer within the title of a source.


According to Jones (1998), "Students often had difficulty using APA style, especially when it was their first time" (p. 199).

MLA Style

Begin your reference page on a separate page at the end of your research paper. It should have the same one-inch margins and last name, page number header as the rest of your paper. Double space all citations, but do not skip spaces between entries.

Begin your citation with the author's last name. Spell out the author's first name and follow with additional authors, separated by commas. End author citations with a period. Follow with the article cited, placed in quotation marks, ending with a period. Italicize the publication name and follow with the date of publication and a colon followed by the pages cited. End the reference by listing the medium of publication. Remember to indent the second line of the citation one-half inch from the left margin.


Author(s). "Title of Article." Title of Periodical Day Month Year: pages. Medium of publication.

Cite sources in text by placing the last name of the first author cited with the page number where the quote or information is found in the publication at the end of the sentence. Place the author name followed by the page number in parentheses.


  • You need to follow different citation guidelines depending on what source materials you are citing -- such as a book, journal article, or online article -- so if you are unsure of the proper format, consult the appropriate style guide.