BROOKS, Courtney G.; GRIMWOOD, James M.; SWENSON, Loyd S. Chariots for Apollo: A History of Manned Lunar Spacecraft [online]. NASA, 1979 [cit. 2011-11-05]. Kapitola Selecting and Training Crews. Dostupné online. (anglicky)
history.nasa.gov
BROOKS, Courtney G.; GRIMWOOD, James M.; SWENSON, Loyd S. Chariots for Apollo: A History of Manned Lunar Spacecraft [online]. NASA, 1979 [cit. 2011-11-05]. Kapitola Selecting and Training Crews. Dostupné online. (anglicky)