On the "Fundamental Principle" of L. Ehrenpreis
In: Partial differential equations : papers presented at Stefan Banach International Math. Center at the semester "Partial differential equations" held Sept. 11 - Dec. 16, 1978 (Banach Center publications : 10), Jg. 1983, S. 185-2012009
Propagation of discontinuities in wave fields
In: Proceedings on "Model Optimization in Exploration Geophysics" (6th International Seminar, Berlin, February 1988), Jg. 1989, S. 31-392009