--- often attributed to Dr. David T. Hulett, authority on risk; however, in "What Should We Do with Unknowns in Schedule Risk Analysis?," (PM World Journal, Vol. IV, Issue VIII – August 2015), he cites a reference I haven't been able to find online:
Moses, Lincoln
Energy Information Administration Annual Report to Congress
Volume 3, Administrator’s Message
1977 US Government Printing Office, Washington, DC
