I have a book of cryptogram puzzles. Is there any such thing as selling a copyright?

I think you might need a literary agent. Sorry, but I have no idea as to how to contact one. I can ask my daughter if she still has hers and post tomorrow or Saturday if you want.

Try Writer's Market and Writer's Digest for potential markets & lists of agents. Both should be available at your local bookstore/library, and both have web sites. You might also consider self-marketing/self-promoting through Lulu.com or CreateSpace (the latter is an Amazon affiliated competitor to Lulu).

Vasily