Skip to Main Content
We are working to upgrade the research experience by making ongoing improvements to our Research Guides.
You may encounter changes in the look and feel of the Research Guides website along with structural changes to our existing guides. If you have any questions or concerns about this process please let us know.

The Literature Review


Scholarly, professional literature falls under 3 categories, primary, secondary, and tertiary.  Published works (also known as a publication) may fall into one or more of these categories, depending on the discipline.  See definitions and linked examples of primary, secondary, and tertiary sources.

Differences in Publishing Norms by Broader Discipline 

Scholarly and professional communication norms can be different among various disciplines.  For instance, scholars in political science or law will generally publish their knowledge and research differently than those in chemistry or physics.  To show these distinctions, links to examples are provided for primary, secondary and tertiary sources.  The broader disciplines of business, education, and social science tend to use publications from both the sciences and humanities.

If you are in STEM or Nursing, see these examples of primary, secondary and tertiary literature within your disciplines:

Primary Sources

Image:  Typewriter, by DanielMcCullough, Permission by license.

A primary source is a document or work where its author had a direct interaction or was involved with what was studied or created.  These sources are recommended when you need to get information or findings that are a direct result or finding from a study, research, or creation.   A primary source can also be an actual creative work or original material.


Science / Health Sciences:

Secondary Sources

Image:  Library stacks.  Permission by  license.

A secondary source is a document or work where its author had an indirect part in a study or creation; an author is usually writing about or reporting the work or research done by someone else.  Secondary sources can be used for additional or supporting information; they are not the direct product of research or the making of a creative work.


Science / Health Sciences:

Tertiary Sources

Tertiary Books Encyclopedia Set

Image:  Encyclopedias, by StockSnap, Permission by  license.

A tertiary source provides agreed-upon facts like measurements, dates, and definitions.  They are usually known as reference works and include the following:

  • Encyclopedias
  • Almanacs
  • Standards:  a document with specifications that create rules, guidelines or characteristics to ensure that materials, processes, or services are fit for their purpose.  They are established by a professional organization to provide a baseline of acceptable quality.
  • Handbooks and manuals:  a resource that summarizes major topics or processes within a field.  These often provide established measurements, definitions or research methods.
  • Pathfinders (Research Guides): a list of recommended information sources on a topic or discipline.