We regularly get requests for finding information about quotes: the correct wording, its origin, or the author of a quote. Sometimes we find what we're looking for and sometimes we don't. Quotes are a tricky one. While we rely mainly on the resources here at the University of Minnesota Libraries, they too can be limiting. That is why when we come across a good resource, especially for quotes, we bookmark them for future use. We also like to share the knowledge of resources available, especially when they are free!
Here is one we have come across as an addition to our arsenal of quotation resources: The Literature Network, http://www.online-literature.com/advancedsearch.php. This is a good resource when you want to locate a particular quotation by searching through a database of the author's works. As I mentioned, it is a free resource so you will have to deal with banner ads and the ocassional pop-up, but still, it's a good resource.