Primary, Secondary, and Tertiary Sources Sources of information or evidence are often categorized as primary, secondary, or tertiary material. These classifications are based on the originality of the material and the proximity of the source or origin.
The entries starting with Scarborough, Yatesburg, and Robinson are books. They all have publishing companies. The first is from a periodical. The 19.2 tells you the issue. The ones with Web are from the internet.
