What has the author R G LeTourneau written?

Robert Gilmour LeTourneau (1888–1969), also known as "R.G.", was an American industrialist and inventor. He founded the LeTourneau Company, which manufactured earthmoving equipment. LeTourneau held over 300 patents and was involved in the development of many construction and mining machines, including the Tournapull, the Tournacrane, and the LeTourneau L-235 scraper. He also wrote several books, including Mover of Men and Mountains (1957), which chronicles the history of his company and his life.