
Charles Eastman
Charles Alexander Eastman was an American physician, writer, and social reformer. He was "one of the most prolific authors and speakers on Sioux ethnohistory and American Indian affairs" in the early 20th century.
Excerpt from Wikipedia, available under CC BY-SA 4.0.
Books

The Essential Charles Eastman (Ohiyesa)
2007
ISBN 9781933316857