TY  - JOUR
AU  - D.M. Jr. Burns
AU  - C.L. Epstein
TI  - A global invariant for three dimensional CR-manifolds.
JO  - Inventiones mathematicae
PY  - 1988
SP  - 333
EP  - 348
VL  - 92
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM_1988__92_1_143570/
ID  - IM_1988__92_1_143570
ER  -