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.