About.com all-in-one search:
All in one search page allows you to search various quotation search
engines.
http://quotations.about.com/arts/quotations/library/blsearch.htm
Bibliomania:
Hundreds of searchable full-text works of writing.
http://www.bibliomania.com/
Maridadi.com: Quotations:
Offers a multi-search of major search engines and specialist sources
including The Quotations Page, Bartlett's Familiar Quotations,
Quoteland, MotivationalQuotes, and Project Gutenberg.
http://www.maridadi.com/quotations/
