Bernard Taub Feld
T. Mannel
Summer Institute in Theoretical Physics Centro de Investigación y de Estudios Avanzados del IPN 1973.
H. H. Aly
George W. S. Hou
Lars Bergström
Murray Gell-Mann
Aspen Winter Physics Conference (1st 1985)
R. E. Lechner
Heisenberg Symposium (1981 Munich, Germany)
S. N. Lyle