There seems to be some assumption here that books are named by their ordering of volumes. But I might know the name of a book and not its contents, so I'd need

There seems to be some assumption here that books are named by their ordering of volumes. But I might know the name of a book and not its contents, so I'd need to look up the contents. (Of course, this is silly if you have every possible book, because any other naming scheme means most names will be longer than the books themselves....)