[curtiss]

I'm still somewhat at a loss as to how you are generating the phrases you're trying to match. Are your users typing in a phrase that you're trying to match against various sources, or are you simply trying to find common phrases between all of the books you have in the database?

If your users are typing in the phrases, the best way to go about this is to use a fulltext search within your MySQL database. If you're simply trying to compare two or more database results to find common phrases, I honestly can't think of a good way to do so, unfortunately.