R. M. STERN, J. J. PERRY, and D. S. BOUDREAUX
Rev. Mod. Phys. 41, 275 (1969) - Published 1 April, 1969
M. H. ERNST, L. K. HAINES, and J. R. DORFMAN
Rev. Mod. Phys. 41, 296 (1969) - Published 1 April, 1969
J. ROSS MACDONALD
Rev. Mod. Phys. 41, 316 (1969) - Published 1 April, 1969
H. GROTCH and D. R. YENNIE
Rev. Mod. Phys. 41, 350 (1969) - Published 1 April, 1969