TY  - JOUR
AU  - Martin Scharlemann
TI  - Smooth spheres in IR4 with four critical points are standard.
JO  - Inventiones mathematicae
PY  - 1985
SP  - 125
EP  - 142
VL  - 79
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM_1985__79_143188/
ID  - IM_1985__79_143188
ER  -