Copyright doesn't provide as much protection as you think it does. It prevents them from using your actual copyrighted sentences, descriptions, writing, etc.--but it doesn't protect your name, the name of your book, or the "researach" (i.e. the basic information) behind the book. To use an example: I am now reading "The Finest Hour" by Tougias and Sherman, the story of a famous Coast Guard rescue (and the basis for the pending movie). I could create and advertise a tour to see the Coast Guard boat and station involved in the rescue (even though I only learned about it through the book) and could market it as "see the facilities and vessels involved in the rescue from 'The Finest Hour' by Tougias and Sherman'" and that would be legal. What I could not do would be to reproduce any paragraphs from the book for my marketing materials--that would violate copyright, since copyright protects a given creative work, not the underlying names, events, and facts.