Generally, comp books should have been published within the last 5 years. When I needed comp books for a sub last month and I couldn't go browse in the library or bookstore because I was self-quarantining due to the pandemic, I called our local library and explained my dilemma. The children's librarian was very helpful. She researched their data base and emailed me a list of books. I then ordered a bunch of them from the library for drive-by pick up, read through them, and found 3 to use for my needed comp titles. YAY for wonderful librarians!