Secondary sources are when authors refer to other authors in their works. This means that when you use a citation provided by a secondary source author, you are citing the original author indirectly.
Use secondary sources wisely.
Be aware that when you cite a secondary author, the original information may have been taken out of context. This is why you should always seek out the original author's work where possible.
Only cite secondary sources if the original source is:
The citation should include:
See in-text citations for information and examples of other types of citations.