TY  - JOUR
AU  - V. Ya. Ivrii
TI  - The Cauchy problem for nonstrictly hyperbolic equations of second order
JO  - Doklady Akademii Nauk
PY  - 1971
SP  - 778
EP  - 781
VL  - 201
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1971_201_4_a3/
LA  - ru
ID  - DAN_1971_201_4_a3
ER  -