Students working at table

Principles of Citing Sources: Signaling Citation Styles

At a Glance

  • In academic writing, nearly every reference to a source has two parts: the indication in the body of your paper that you’re referring to a source and the publication information a reader needs to track that source down later. 
  • The three citation styles used in this guide—MLA, APA, and Chicago style footnotes—use different methods for that initial signal that a source is being used.
  • For more information on how to signal different citation styles for a variety of source types, visit the Writing Center Handouts page. 

Signaling Different Citation Formats

MLA Citations

Both MLA and APA are what’s known as “in-text” citation styles, which means that you give some brief information about the source directly in your sentence or paragraph, but refer readers to a section later in your paper for the full publication details. (MLA calls this later section the “Works Cited,” while APA calls it the list of “References.”) In MLA format, references to a source should mention the author’s name and the exact page you’re using directly in your paragraph. You would normally give the page number in parentheses, directly after you quote or paraphrase the source. You may give the author’s name in the parentheses, too, or include it in your sentence. Here are two very simple examples of how this might look:

Signaling Sources - MLA1

MLA In-Text Citation with author’s name in parentheses

Signaling Sources - MLA2

In-Text Citation where author’s name is included in lead-in


In either case, the reader will know to look for “Fiedler” in your Works Cited to find the rest of the information about your source. 

APA Citations

In APA format, references to a source should mention the author’s name and give the publication year of the source. You would normally give the year in parentheses. You may give the author’s name in the parentheses, too, or include it in your sentence. (If you include the name in your sentence, give the year directly after; if you put the name and year in parentheses, put them at the end of the sentence where you quote or paraphrase the source.) Here are two very simple examples of how this might look:

Signaling Sources - APA1

APA citation with year directly after source name and page number for direct quotation provided at end of sentence

Signaling Sources - APA2

APA citation with author last name and year in parentheses


In either case, the reader will know to look for “Douglas” in your References list to find the rest of the information about your source. 

Chicago Style Citations

The alternative to “in-text” citations are footnotes, which give publication information at the bottom of the page. This guide describes Chicago style footnotes (see Understanding Different Citation Styles for more information). With footnotes, you are not required to mention the author, page, or year directly in your sentence. You only need to include the footnote number and to put the author and page number at the bottom of the page. But you might include one or more of these details directly in your sentence, anyway, depending on what you were trying to emphasize about the quotation. In addition to including footnotes throughout your paper, you should also include a list of all sources cited at the end of your Chicago style paper. Rather than “Works Cited” or “References,” Chicago style calls this list a “Bibliography.” Sometimes an instructor may ask that your Bibliography include all sources consulted during your research, not just those cited in your final draft, so make sure to ask about expectations before submitting papers for each class. Below are some simple examples of how to cite sources using footnote style.

Signaling Sources - Chicago0

In-text footnote introduction

Signaling Sources - Chicago1

Footnote placed in the footer at bottom of page

Readers will look for “Blight” in your paper’s Bibliography.