Every academic by now knows the routine. You come across a pithy quote
by a famous author that doesn't sound quite right. No source text is
given. A general web search yields ten pages of links to self-help
sites or quote-a-day webpages. A Google Books or Google Scholar search
will offer links to published self-help books or articles going back
to the 1980s. None of the sites will offer a full citation or even
gesture toward a source text. You sadly conclude that the quote is
bogus. Such is academic life in the age of the search engine.
-- Hollis Robbins. "Familiar (Mis)Quotations"
Inside Higher Ed. (April 8, 2011)
http://www.insidehighered.com/views/2011/04/08/robbins