"Interview with the 1988 Nobel Laureate in Physics, Jack Steinberger". 58th Meeting of Nobel Laureates in Lindau, Germany, www.nobelprize.org. July 2008.
"Physics, in What is Science?: Twelve Eminent Scientists and Philosophers Explain Their Various Fields to the Layman". Book by James Roy Newman, published by Simon and Schuster, p. 102, 1955.