Question

When is it unnecessary to follow a direct quotation with a parenthetical citation that includes the name of the source?

Answer 1

Citation is unnecessary for familiar proverbs, well-known quotations, and common knowledge.

Answer 2

when you introduce the quote with the author instead of putting it at the end. For example
Smith (2000) noted that “monkeys are cute” while Jay (2002) argues they “are fluffy”.
Vs
It is argued that “monkeys are cute” (Smith, 2000) and are also “fluffy” (Jay 2002).