TY  - JOUR
AU  - V. Ya. Ivrii
TI  - Differential equations, with multiple characteristics, that have no solutions
JO  - Doklady Akademii Nauk
PY  - 1971
SP  - 279
EP  - 282
VL  - 198
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1971_198_2_a5/
LA  - ru
ID  - DAN_1971_198_2_a5
ER  -