For those who are also interested in the Mark Diedrich books, I would like to let you know, that Mark Diedrich mailed back to Kingsley in the meantime. The Mni Wakan Oyate book should be available through the Cankdeska Cikana Community College at Fort Totten. I´ll try to connect to the college president and ask if the book is available.
The book about Little Paul was published electronically by Alexander Street Press, but it has not yet been published in paper by Mark Diedrich (Coyote Books). Unfortunately he can't say when it will be published.