Aldous Huxley (1937). “Ends and Means: An Inquiry Into the Nature of Ideals and Into the Methods Employed for Their Realization”, p.358, Transaction Publishers
"Classroom Without Walls". Explorations Magazine, Volume 7, 1957; reprinted in "Explorations in Communication" edited by E. Carpenter and M. McLuhan, 1960, and in "McLuhan: Hot and Cool" edited by Gerald Emanuel Stearn, 1967.
George Washington, David Maydole Matteson, United States George Washington Bicentennial Commission (1931). “The writings of George Washington from the original manuscript sources, 1745-1799”