If you are using a library to help find what you need, you will need to find what you need in with all the other books! Here is a guide that explains how libraries shelve their non-fiction fact books. They are shelved with numbers and letters on the spine, and topics all have a number and the books are put on the shelf by topic. Good news- you will find all the books on a topic together in one place! And in more good library news- there are usually staff around in libraries who are happy to help you find what you need. And that is why we still love libraries!