http://www.amazon.com/gp/product/B00435J7WU/
http://www.amazon.com/gp/product/B005SFSCOI/
http://www.amazon.com/gp/product/B005FIPM3M/
http://www.amazon.com/gp/product/B003YV18OO/
http://www.amazon.com/gp/product/B004FPQLCM/
I live in Australia and I get the message "Sorry, this title is not available in your region" for each of these Audible audiobooks. But I suspect that they were never released on Audible at all because they are all available as MP3 CDs, which would make any region lockout pointless.
If you live in America, can you tell me if these audiobooks are available for purchase?