I'd like to add to this thread that there is a network of used/rare/out-of-print book dealers whom deals internationally and is reportedly pretty good for finding most anything that the major chains can't or won't supply.
http://www.abebooks.com/
Had a good experience dealing through that when I wanted to find a very particular eskimo book that's just plain tough to get a copy of outside of Alaska. Others I know has used them to get a copy of technical or special books available only internationally. The major bookstore chains spent 8 weeks looking for the eskimo book but failed. abebooks.com listed _53_ copies ready for immediate sale!!!! I had it in my possession 3 days later, after ordering through abebooks.com.
So you might find the books you seek at that web site.
Explicit disclaimer: no relationship to them or any of the dealers as anything other than a satisfied one-time customer.