I've got a couple upcoming books which feature chapter quotes: quotes from famous literary figures at the head of each chapter/section head.
The problem is, I want to research the quotes I've found to ensure they're correct, but so far, I've been unable to find a reliable reference to use. There are SO many people posting graphics of 'famous' quotes (often misstated) that it's almost impossible to search for the original source of any single quote. Also, the majority of the quote references focus on old (18th and early 19th century) works, rather than any thing recent (i.e. anything since the 1970s).
Does anyone have any clue how to research that a given quote is authentic, or even where it originated?