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Identify Primary, Secondary, Tertiary Sources

Learn about primary, secondary, and tertiary sources.

What you'll find on this page

On this page, you'll learn:

  • what tertiary sources are and what they look like in different disciplines

  • where to find tertiary sources

  • how to use tertiary sources

  • additional tips to help you identify whether a source is tertiary 

What are tertiary sources?

Tertiary sources provide overviews and context on a topic but generally no original material on that topic. They are often also referred to as "reference sources."

Like primary and secondary sources, tertiary sources may look different depending on your discipline. For example:

In STEM & Medical Fields In the Humanities and Social Sciences
Textbooks Textbooks
Specialized encyclopedias Encyclopedias
Manuals Bibliographies
Specialized dictionaries Indexes
Guides Literature reviews
Fact books Fact books

Where to find tertiary sources

How to use tertiary sources

Tertiary sources are mainly used for the following reasons:

  • to get background information on a topic

  • to quickly find additional sources about a topic

  • to learn the meanings of technical language or jargon in other sources on your topic


Tertiary sources are not usually cited in papers because they do not have original ideas. However, you should still provide a quick summary of any background information that is necessary for your reader to understand your argument. They often contain useful statistics or historical data which provide important context to your research topic. Language you can use to provide these summaries include:

  • A number of __________ have recently suggested that ________.

  • The standard way of thinking about X has it that ________.

  • Many people assume that ________.

  • Studies of X have indicated ________. It is not clear, however, that this conclusion applies to _______.

Pro tips

You probably already know that Wikipedia is not a scholarly source you should cite in a research paper. However, it can be a great way to introduce yourself to topics with which you are not already familiar. Most Wikipedia articles also contain references to scholarly sources that you can cite in your own paper; just be careful to read the actual cited source to verify the information referenced in Wikipedia is correct.