I, too, have found a source for the Oxford books, but fourth edition/revision. I think circa 2008, if memory serves me right. Does anybody know exactly what, if anything, is obsolete? I've heard that Airlaw 01 is the most likely to be out of date, but I have no specifics. I'm about to begin DL with CATS, so any glaring inaccuracy is going to come up upon reading, better safe than sorry.