TY  - JOUR
AU  - Rainer Felix
TI  - Differential operators of the first order with degenerate principal symbols
JO  - Banach Center Publications
PY  - 1992
SP  - 147
EP  - 161
VL  - 27
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/-27-1-147-161/
DO  - 10.4064/-27-1-147-161
LA  - en
ID  - 10_4064__27_1_147_161
ER  -