Final answer:
Parenthetical references are placed before the sentence's end punctuation for all citations except quotations that are set off from the text.
Step-by-step explanation:
Parenthetical references are placed before the sentence's end punctuation for all citations except quotations that are set off from the text. For paraphrases, summaries, and quotations that run in with the text of the paper, the parenthetical reference is placed before the sentence's end punctuation.
For example, if you are paraphrasing or summarizing a source, you would place the parenthetical reference before the sentence's end punctuation: (Author's Last Name page number).
However, if you have a quotation that is set off from the text, also known as a long quotation or block quotation, you would place the parenthetical reference after the sentence's end punctuation. In this case, there is no need to include the page number since the entire quotation is already cited.