Neufeld, Michael J. and Charles, John B. 2017. "The Invention and Diffusion of Neutral Buoyancy Training." In History of Rocketry and Astronautics: Proceedings of the Forty-Ninth History Symposium of the International Academy of Astronautics. Inbar, Tal, editor. 59–71. San Diego: Univelt, Inc., for the American Astronautical Society.