Amber I use this link: http://www.copyright.gov/records/cohm.html As a practical matter, if a book has an ISBN, there likely is no reason to check further. Similarily, books from mainstream publishers such as Harper Collins, Thomas Nelson, et al don't have problems. Where the questioning of copyright seem to occur are with self-published books and those from non mainline publishers. A lot of issues seem to arise with secondary Christian publishers who copyright their materials, of course, but don't necessarily follow industry standard registration norms. A note to book scanners: I would also suggest to check copyright prior to kscanning a book. If the goal is BookShare accpetance, I would think twice before scanning something which might lead to questioning and possible rejection.