TY  - JOUR
AU  - Z. D. Usmanov
TI  - On~infinitesimal deformations of surfaces of positive curvature with an isolated flat point
JO  - Sbornik. Mathematics
PY  - 1970
SP  - 595
EP  - 614
VL  - 12
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1970_12_4_a7/
LA  - en
ID  - SM_1970_12_4_a7
ER  -