A tertiary source is an index or textual consolidation of already published primary and secondary sources[1] that does not provide additional interpretations or analysis of the sources.[2][3] Some tertiary sources can be used as an aid to find key (seminal) sources, key terms, general common knowledge[4] and established mainstream science on a topic. The exact definition of tertiary varies by academic field.
Academic research standards generally do not accept tertiary sources such as encyclopedias as citations,[4] although survey articles are frequently cited rather than the original publication.
Overlap with secondary sources
As is also the case with distinguishing primary and secondary sources in some disciplines,[5] there is not always a clear distinguishing line between secondary and tertiary sources. Depending on the topic of research, a scholar may use a bibliography, dictionary, or encyclopedia as either a tertiary or a secondary source.[1] This causes some difficulty in defining many sources as either one type or the other.
In some academic disciplines, the differentiation between a secondary and tertiary source is relative.[1][3]
In the United Nations International Scientific Information System (UNISIST) model, a secondary source is a bibliography, whereas a tertiary source is a synthesis of primary sources.[6]
Types of tertiary sources
 | This section needs additional citations for verification. (May 2021) |
Tertiary sources can come in book form or as an online resource. Tertiary sources in book form are frequently organised in alphabetical order, whereas an online tertiary source may be searchable by keyword.[7]
Examples of tertiary sources include; reference books, encyclopedias, dictionaries, some textbooks,[1][7] abstracts, directories, factbooks, handbooks, manuals[8] and compendia. Indexes, bibliographies, concordances, and databases are aggregates of primary and secondary sources and therefore often considered tertiary sources. They may also serve as a point of access to the full or partial text of primary and secondary sources. Almanacs, travel guides, field guides, and timelines are also examples of tertiary sources.
Tertiary sources attempt to summarize, collect, and consolidate the source materials into an overview without adding analysis and synthesis of new conclusions.
Wikipedia is a tertiary source.[9]
See also
References
- ^ a b c d Primary, secondary and tertiary sources. Archived 2013-07-03 at the Wayback Machine". University Libraries, University of Maryland. Retrieve 07/26/2013
- ^ "Tertiary Information Sources". Old Dominion University -- ODU Libraries. September 2012. Archived from the original on 6 September 2019. Retrieved 20 June 2013.
- ^ a b "Tertiary sources Archived 2014-11-06 at the Wayback Machine". James Cook University.
- ^ a b "Primary, Secondary, and Tertiary Resources". University of New Haven.
- ^ Kragh, Helge (1989). An Introduction to the Historiography of Science. Cambridge University Press. p. 121. ISBN 0-521-38921-6. Retrieved 28 November 2025.
- ^ Søndergaard, T. F.; Andersen, J.; Hjørland, B. (2003). "Documents and the communication of scientific and scholarly information: Revising and updating the UNISIST model". Journal of Documentation. 59 (3): 278. doi:10.1108/00220410310472509. S2CID 14697793.
- ^ a b Bombaro, Christine (2012). Finding History: Research Methods and Resources for Students and Scholars (1st ed.). Lanham, MD: Scarecrow Press, Incorporated. p. 57. ISBN 978-0-8108-8379-6.
- ^ Harris, Bitonti, Fleisher, Binderkrantz (2022). The Palgrave Encyclopedia of Interest Groups, Lobbying and Public Affairs (1 ed.). Springer. p. 1345 Switzerland. ISBN 9783030445553. Retrieved 28 November 2025.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ "Primary, Secondary, and Tertiary Sources". University of Minnesota Crookston. Retrieved 19 April 2023.
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