TY  - JOUR
AU  - P. I. Plotnikov
TI  - Equations with a variable direction of parabolicity and the
JO  - Doklady Akademii Nauk
PY  - 1993
SP  - 691
EP  - 693
VL  - 330
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1993_330_6_a4/
LA  - ru
ID  - DAN_1993_330_6_a4
ER  -