editors, H. Latal and H. Mitter. edited by W. Oettli and K. Ritter. editors, C. Vidal and A. Pacault. editors, C. Jaffiol and G. Milhaud. editors, G. Giraldo and E. Beth. editors, E. Klose and B. Wilhelmi. editors, J. Narayan and T. Y. Tan. editors, H. Walther and K. W. Rothe. editors, A. Crucq and A. Frennet. editors, R. Vanselow and R. Howe.