How do I find an old book no longer in print?

My mom's biological father wrote an autobiography of sorts while serving time in a prison in Indiana. It was part of his prison ministry and was written sometime in the 70's. My mother read it once and then gave it back to her sibling who has since lost it. Seeing as she has almost no memories of her biological father I thought to find this book would be a great gift to her. She said that she thought there was only about (at most) 1,000 printed. It did have an ISBN number. His name was Roger Kerr. I have tried bookfinder.com, goodreads, half.com, ebay, etc. To no avail. Does anyone know of an online resource to search for books like this? It's very possible there are no remaining copies, but just in case there are I thought it couldn't hurt to try. My mom does not remember the title of the book. Thanks!|||You migjt try the prison library. Failing that, go to a regular library and ask suggestions for tracing a book. Good luck with your search.|||Go to a real book store and ask them. They usually have connections that regular people do not have.|||This is a long shot but if you haven't already see if there are on-line resources that would get you some from the Library of Congress (if it got an ISBN, it almost certainly was filed there, too) You might get the title that way and that would make the search easier.