Bleuler, K., Petry, H. R., & Reetz, A. (1978). Differential geometrical methods in mathematical physics II: Proceedings, University of Bonn, July 13-16, 1977. Springer-Verlag.

Bleuler, Konrad, Herbert Rainer Petry, and Axel Reetz. Differential Geometrical Methods in Mathematical Physics II: Proceedings, University of Bonn, July 13-16, 1977. Berlin ; New York: Springer-Verlag, 1978.

Bleuler, Konrad, et al. Differential Geometrical Methods in Mathematical Physics II: Proceedings, University of Bonn, July 13-16, 1977. Springer-Verlag, 1978.