Melvin Schwartz
Samios, N. P., Plano, R., Prodell, A., Schwartz, M. and J. Steinberger.    "The Parity of the Neutral Pion and the Decay pi{sup 0} Yields 2e{sup +} + 2e{sup -}", Nevis Cyclotron Laboratory, Columbia University, United States Department of Energy (through predecessor agency the Atomic Energy Commission), Office of Naval Research, (January 1962).