Differential geometrical methods in mathematical physics :
Differential geometrical methods in mathematical physics : Proceedings of the Symposium held at the University of Bonn, July 1-4, 1975. /
- berlin : Springer-Verlag 1977.
FISICA MATEMATICA--CONGRESOS.
GEOMETRIA DIFERENCIAL--CONGRESOS.
FISICA MATEMATICA--CONGRESOS.
GEOMETRIA DIFERENCIAL--CONGRESOS.