Document which is based on the study and analysis of primary sources and/or secondary sources. A bibliography, for example, would be called a tertiary source. Compare Primary Source; Secondary Source.

Where a primary source presents material from a first-hand witness to a phenomenon, and a secondary source provides commentary, analysis and criticism of primary sources, a tertiary source is a selection and compilation of primary and secondary sources. While the distinction between primary source and secondary source is essential in historiography, the distinction between these sources of evidence and tertiary sources is more peripheral, and is more relevant to the practice of scholarship than to the content.