Citations consist of standard elements, and contain all the information necessary to identify and track down publications, including:
It doesn't matter where you get the information you are using- When in doubt cite it:
You do not need to cite:
*Widely-known, generally-accepted information that is not attributable to one source.
Citations may look different, depending on what is being cited and which style was used to create them. The citation style usually depends on the academic discipline involved.
For your HIS 140 research assignments, you are required to cite your sources using the Chicago Manual of Style.