For someone in the field, teaching is work, while telling people they are wrong isn't. Unless you are paying good money, you don't have a right to the former in

For someone in the field, teaching is work, while telling people they are wrong isn't. Unless you are paying good money, you don't have a right to the former instead of the latter. In any event, the GP (note: not the same as the OP) could just look for himself on the shadow libraries, which now have pretty much everything.