TY  - JOUR
AU  - É. V. Nikol'skii
TI  - The dynamic Fermat and Huygens principles for a second-order scalar three-dimensional equation of general type
JO  - Doklady Akademii Nauk
PY  - 1985
SP  - 284
EP  - 289
VL  - 285
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1985_285_2_a5/
LA  - ru
ID  - DAN_1985_285_2_a5
ER  -