classic papers of the week -- 48

A planetary system around the millisecond pulsar PSR1257 + 12

• Wolszczan, A. (Arecibo Observatory, PR); Frail, D. A. (National Radio Astronomy Observatory, Socorro, NM)

Internal Pair Production Associated with the Emission of High-Energy Gamma Rays

• Kroll, Norman M. (Columbia University, New York, New York); Wada, Walter (Naval Research Laboratories, Washington, D.C.)

Parity of the Neutral Pion

• Plano, R.; Prodell, A.; Samios, N.; Schwartz, M.; Steinberger, J. (Columbia University, New York, New York)