TY  - JOUR
AU  - Z. D. Usmanov
TI  - On~a~problem concerning the deformation of a~surface with a~flat point
JO  - Sbornik. Mathematics
PY  - 1972
SP  - 61
EP  - 81
VL  - 18
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1972_18_1_a3/
LA  - en
ID  - SM_1972_18_1_a3
ER  -