I bought mine at PetEdge, but if you don't have a big order, the handling charge is outrageous. I believe that
www.sitstay.com also carries them and maybe the Jeffers pet supplies site.
If you can't find them, let me know, I am getting ready to place an order with PedEdge and I could tack on some for you..... The packages are 2 ounces so it wouldn't cost me much to ship to you....