Which of the founders of the of the Creation Research Society and the Institute for Creation Research, also co-authored a book, that according to Ronald Numbers, elevated young earth creationism "to a position of fundamentalist orthodoxy." ?
The Genesis Flood: The Genesis Flood: The Biblical Record and its Scientific Implications is a 1961 book by young earth creationists John C. Whitcomb and Henry M. Morris that, according to Ronald Numbers, elevated young earth creationism "to a position of fundamentalist orthodoxy." Henry M. Morris:  He was one of the founders of the Creation Research Society and the Institute for Creation Research.
Henry M. Morris