Nonlinear Interactions of Three Wave Packets in an Inhomogeneous Medium
A. H. Reiman, A. Bers, and D. J. Kaup
Phys. Rev. Lett. 39, 245 (1977) - Published 1 August, 1977
Supergravity Has Positive Energy
S. Deser and Claudio Teitelboim
Phys. Rev. Lett. 39, 249 (1977) - Published 1 August, 1977