Someone posted here that there are four or five books acnowledged in the Bible that all people would know at the time. I researched it on wikipedia. It is true. These books may have been considered more sacred than the Bible to Jews and other Middle Eastern inhabitants. The Bible accounts just names them b/c everyone they expect to read would have already known about these books.
So far no one has found any of the books or even comments referring to them in ancient literature beyond the Bible. People are hunting for them. If they ever surface, or a later writing repeats the iinfo, it could utterly transform what we believe in the Bible.