Question: What was the name of the book written by Hilda Neihardt's father that was based on the second cousin of the war chief Crazy Horse?
Sentence (from "Hilda Neihardt"): Hilda Neihardt (1916–2004) was one of her father John G. Neihardt's "comrades in adventure," and at the age of 15 accompanied him as "official observer" to meetings with Black Elk, the Lakota holy man whose life stories were the basis for her father's book, "Black Elk Speaks" and for her own later works.
Relevant evidence: Yes