TY  - JOUR
AU  - V. I. Bernik
AU  - É. I. Kovalevskaya
TI  - Two-dimensional extremal surfaces with jointly extremal partial derivatives
JO  - Matematičeskie zametki
PY  - 1991
SP  - 14
EP  - 19
VL  - 50
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZM_1991_50_2_a1/
LA  - ru
ID  - MZM_1991_50_2_a1
ER  -