%0 Journal Article
%A A. Pilś
%T The characteristic equation for partial differential equations of the first order
%J Colloquium Mathematicum
%D 1958
%P 223-226
%V 6
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.4064/cm-6-1-223-226/
%R 10.4064/cm-6-1-223-226
%G en
%F 10_4064_cm_6_1_223_226