You don't document your independent material—your thoughts, observations, or insight. You can refer to your own experience or have new insight into a topic that you've studied for a long time.
In the eighth edition of The Little, Brown Handbook (Instructor's Annotated Edition), the authors cite a quotation from Jessica Mitford's Kind and Usual Punishment. First, they give her quotation (see below) and then show plagiarism by the revisionist changing few words. They follow that by paraphrasing and citing the reference.
Original: The character and mentality of the keepers may be of more importance to understanding prisons that the character and mentality of the kept.
Paraphrasing: According to one critic of the penal system, the psychology of "the kept" may be less about prisons than the psychology of "the keepers." They follow that by citing the Mitford Book.
Summarizing: One critic of the penal system maintains that we may be able to learn less from the psychology of the prisoners than from the psychology of the prison officials. (Again they cite Mitford.)
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 The Little, Brown Handbook, eighth Edition, by H. Ramsey Fowler, and Jane E. Aaron, (Boston: Little, Brown, 2001) page 689–690.