TY  - JOUR
AU  - Lawrence. Corwin
AU  - B. Helffer
TI  - Smoothness and analycity for solutions of first order systems of partial differential equations on nilpotent Lie groups.
JO  - Inventiones mathematicae
PY  - 1985
SP  - 205
EP  - 216
VL  - 81
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM_1985__81_143253/
ID  - IM_1985__81_143253
ER  -