The purpose of these sources are to index, abstract, organize, compile, or condense other sources.
Tertiary sources usually are not authored by one person, but many.
Repackaged primary/secondary sources in one quick reference source.
May provide subjective commentary on primary/secondary sources.
Examples:
- Dictionaries
- Encyclopedias
- Almanacs
- Fact books
- Directories
- Guidebooks
- Manuals
- Indexing and Abstracting sources