Lascar Richard Propagation des singularites des solutiond' equations pseudo-difeerntielles a caracterstiques de multipilcites variable - Berlin Springer Verlag 1980 - viii, 237p. cm. - Lecture notes in mathematics; 856 . Standard No.: 22823 Source: Textual Subjects--Topical Terms: Group theory Dewey Class. No.: B27, 122M0