There isn't one!
Recipe drops are completely random and can drop off of any two-legged mob of a like level.
Your best bet is to find an area with humanoid mobs of the highest level you can handle and then just grind them out till you get what you want!
Also, most recipes tend to be very cheap on the AH (there is little profit in most of them) so you should be able to buy most anything you can't find on your own.