Citation, Documentation of Sources

Q. If someone uses multiple quotes that are not interrupted by a separate source, should the citation be with the first quote or the last?

A. If the quotations occur in the same paragraph, it’s usually best to place the note reference number (or parenthetical author-date citation) after the last one. But if the same source is relied on again in a subsequent paragraph, you’ll need to cite it again even if no other cited source has intervened.

A similar approach can work for a series of quotations from different sources in the same paragraph; see CMOS 14.57 for details and an example.