Tertiary Sources: Sources that assemble information from a variety of primary and secondary resources. The viewpoint is general and most removed from the original source.
Examples: Dictionaries, encyclopedias, databases, abstracts,directories, indexes, fact books, almanacs, guidebooks, manuals, textbooks.
Out at the edge in the galaxy of information are tertiary sources. Think about your research process as starting out at the edge and working your way to the middle. Tertiary sources are great places to go for background information on your topic that will help you get the big picture, as well as to start locating your secondary and primary sources.