Citation Styles

How often do I cite?

  • Remember: one citation at the end of a string of sentences or a paragraph cannot “cover” the entire section.
  • Cite a source the first time it is used in each paragraph.
  • Every sentence thereafter in the paragraph that uses information from this same source must contain either a signal phrase or a citation clearly indicating where the information came from.
    • Note: always use a citation (even if you also use a signal phrase) every time you quote material.

Citation Placement in Text

Where in the sentence does my in-text citation go?

  • If you name your source(s) in a given sentence, a parenthetical citation containing only the year always follows immediately after the name(s) of the author(s). Example: In contrast to earlier work by Abbott and Costello (1999), Laurel and Hardy (2008) propose an altogether different model for optimizing hat density …
  • If you do not explicitly name your source(s) in a given sentence, a single parenthetical citation goes at the end of the sentence or clause it covers (Goffman 1974), inside the punctuation, like this (Melville 1851).
    • “If the sentence ends with a quotation, close the quote, then place the citation between the quotation marks and the punctuation, like this” (Woolf 1931, p. 22).
  • Do not insert spaces between a parenthetical citation and the punctuation that follows it.

In the paragraph below, the  parenthetical in-text citations are highlighted in yellow, and the signal phrases are in blue. Note that the second sentence is common knowledge, whereas the final sentence is clearly the opinion of the author.

Red and yellow are the best colors with which to decorate your restaurant because they induce feelings of hunger (Smith and Jones 2009). Consider popular fast-food chains, which often use red and yellow in their advertising and décor. According to Smith and Jones’ study (2009), restaurant customers felt more energized in red and yellow environments, which encouraged them to order more food. The same study indicated that patrons felt relaxed in blue and purple environments, which encouraged them to “spend more time considering the menu options and eat at a slower pace” (p. 452). Although blue décor can give your restaurant a more casual, laid-back feel (Kramer 1999)Smith and Jones believe it encourages patrons to linger at their tables without ordering additional food or beverages. Accordingly, it is difficult to identify a popular chain restaurant that decorates with calmer hues.

Difference between List of References and a Bibliography

  • A List of References includes all works cited in a text
  • A Bibliography lists all works cited and consulted

For papers, check with your professors for their preference. Thesis Processing prefers a List of References for the following: 

  • Thesis
  • Capstone project report
  • MBA report
  • Dissertation

How do I format my full List of References/Bibliography?

Same Author, Multiple Works / Multiple Sources in One Citation

Examples given are for books; follow the appropriate style for the source type you are citing.

Source Generic Example Actual Example

Same author, same year, different sources

  • List sources in alphabetical order by title in the List of References (ignoring initial "a," "an," or "the") and append a lowercase letter to the year.
Source 1

R: Author AA (year + a) Title of Book 1 in Title Case and Italics (Publisher, Place of Publication).

T: (Author year + a)

R: Hawthorne M (2006a) The Cannibal’s Dilemma: An Unnatural History of Four Siblings (Penguin, New York).

T: (Hawthorne 2006a)

Source 2

R: Author AA (year+b) Title of Book 2 in Title Case and Italics (Publisher, Place of Publication).

T: (Author year + b)

R: Hawthorne M (2006b) Having People for Dinner: A Guide for the Home Cook (Penguin, New York).

T: (Hawthorne 2006b)


T (both sources): Author Last Name year + a year + b)

T (both sources): (Hawthorne 2006a, 2006b)

Same author, different year, different sources

  • List sources in chronological order.
Source 1

R: Author AA (year) Title of Book 1 in Title Case and Italics (Publisher, Place of Publication).

T: (Author year)

R: Hawthorne M (2006) Having People for Dinner: A Guide for the Home Cook (Penguin, New York).

T: (Hawthorne 2006)

Source 2

R: Author AA (year) Title of Book 2 in Title Case and Italics (Publisher, Place of Publication).

T: (Author year)

R: Hawthorne P (2008) Regrets (Penguin, New York).

T: (Hawthorne 2008)

T (both sources): (Author year 1, year 2)

T (both sources): (Hawthorne 2006, 2008)

Different authors, different years

  • Place references in alphabetical order and separate them with a semicolon. Ensure all authors appear in the list of references.
T: (Author 1 year; Author 2 year)

T: (Hawthorne 2006b; Norton 1998; Stulberg 2014)


Missing Info

If any information is missing from a source (a journal with no volume number, for example), simply omit that information. For sources consulted in hardcopy, omit the URL and any additional verbiage that introduces it. Anything retrieved online, however, MUST have a link. The only exception is journals retrieved from a subscription database such as ProQuest. 


Title Case: To Capitalize or Not: A Brief Tutorial

Sentence case: To capitalize or not: A brief tutorial

Note: Always format the information in your citations (titles, author names, etc.) according to the requirements of the citation style you are using, regardless of how it appears in the original source.

When Do I Need to Add Page Numbers?

For direct quotes, add page numbers to the in-text citation only.

Example: (Haynes 2009, p. 70)

For book chapters, include page-number range in List of References/Bibliography.

Example: Cordesman AH, Mausner A, Kasten D (2009) Introduction. Python MM, Monty PP, eds. Winning in Afghanistan: Creating Effective Afghan Security Forces (Center for Strategic and International Studies, Washington, DC), 15–25.


  • Include a retrieval date if the source material has no date.
  • Always add a period at the end of the URL.
  • A URL does not belong in an in text-citation. Ever.

Et al.

  • One or two authors:
    • In the reference list, include all of them
    • In the text, include all of them
  • Three to ten authors:
    • In the reference list, include all of them
    • In the text, list only the first author, followed by et al. (“and others”)
  • Eleven or more authors:
    • In the reference list, include only the first seven, followed by et al.
    • In the text, list only the first author, followed by et al. (“and others”)

Author Names

Do not include honorifics (Dr., Col., Professor, etc.) when citing author names.

Secondary Sources

A secondary source is a source that cites some other work that you discuss in your text.

Whenever possible, consult primary sources and your sources’ sources yourself. Upon investigation of the primary source, you may find you disagree with the secondary source author’s analysis or methods. Only use secondary sources when the primary source is unavailable.

How to Incorporate Secondary Sources

The following passage incorporates a properly credited secondary source. The secondary source information is highlighted in yellow; the primary source information is highlighted in blue.

Walker (2014) describes data collected in 1999 by Miguel Roig that correlates students’ inadequate paraphrasing to poor reading comprehension. Citing Roig’s data, Walker explains that “students do in fact possess skills necessary for paraphrasing but … may be impeded from applying those skills when dealing with rigorous text” (p. 2).

Note: Include  only  the  secondary  source  (the  source  you  consulted)  in  your  reference  list. 

No Date Given

To cite an undated document, put the year you accessed the material in parentheses in both in-text citations and the list of references.

Acronyms: Organization as Author

Do not include acronyms with organizations listed as authors in the List of References.

Like this:

R: Department of Defense (2012) Identification (ID) Cards Required by the Geneva Convention. DOD Instruction 1000.01 (Washington, DC).


Not this:

R: Department of Defense (DOD) (2012) Identification (ID) Cards Required by the Geneva Convention. DOD Instruction 1000.01 (Washington, DC).