Consider the size of the DNA "books": for example, the human genome is around 3 GB (uncompressed), much bigger than a single book on your shelf: King James Bible as plain text is around 4 MB (uncompressed), so it's a factor of roughly 1000 times (being always copied in every cell of your body!) and we have many complete copies and versions of older bibles but we still can't completely reconstruct too old versions. But we can have a reasonable reconstruction of the "tree" of the development of the known bibles.

And having just a single page from a bible can tell you quite good where that bible fits in the tree of all known bibles.