There seems to be some controversy over the book that's mentioned in the video (Engelbart Hypothesis)

http://www.dougengelbart.org/library/books-unauthorized.html

"This book is unauthorized. Douglas Engelbart was not an author on this book. Eileen Clegg and Valerie Landau were the sole authors of this book. Listing Doug Engelbart as lead author was one of many problems with this book"