Spencer Weart, Center for History of Physics (2010). "Who Invented the Laser?". Bright Idea: The First Lasers. American Institute of Physics. Archived from the original on May 28, 2014. Retrieved April 29, 2010.
Spencer Weart, Center for History of Physics (2010). "Who Invented the Laser?". Bright Idea: The First Lasers. American Institute of Physics. Archived from the original on May 28, 2014. Retrieved April 29, 2010.
Gould, R. Gordon (1959). "The LASER, Light Amplification by Stimulated Emission of Radiation". In Franken, P.A.; Sands R.H. (eds.). The Ann Arbor Conference on Optical Pumping, the University of Michigan, June 15 through June 18, 1959. p. 128. OCLC02460155.