TY  - JOUR
AU  - B. Z. Shapiro
TI  - Normal Forms of the Whitney Umbrella with Respect to the Contact Group Preserving a Cone
JO  - Funkcionalʹnyj analiz i ego priloženiâ
PY  - 1997
SP  - 91
EP  - 94
VL  - 31
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/FAA_1997_31_2_a14/
LA  - ru
ID  - FAA_1997_31_2_a14
ER  -