Higher Criticism

This may have been discussed already, in which case I would be grateful if you could just give me the link to the thread...

I was reading a book on Biblical Archaeology and the author of the chapter on the patriarchal period relied heavily on the documentary hypothesis/Higher Criticism i.e. the theory that the Pentateuch was written by four different authors. As far as I can see these ideas have been prevalent for some time.

Does anyone know of any books or websites that answer the claims of the theory?