Click on the numbers at the front of the titles on the index, or scroll down the page. Should work.

Here's the URL, in case the blue clicky's a problem: http://www.classical.net/music/comp.lst/works/orff-cb/carmlyr.html

So far as I can see it's the same text used on the records I've got.

Incidentally, for anyone who likes Carmina Burana, this is the book to get hold of, to fill in the background - Helen Waddell - The Wandering Scholars