Audible.com unathorized to sell due to geographical location?

I like to listen to audiobooks on my ipod when I do homework. So I go to audible.com to get audiobooks. Now I want the audiobooks "alex rider" it's a series and is read by oliver chris. But audible says I cannot buy it because of my location. I know what this means, but I would like to know if there is anything I could do to get them. There are some that are read by different people, but only certain books, so is there anyway I could get those books?