000
00319nam a2200121 4500
008
160616s 000 0
245
_a
Second order equations with nonnegative characteristic form
100
_a
Oleinik, O.A
100
_a
Radkevic, E>V
500
_a
B334,1,1 L3
942
_c
BK
_2
BK3838
080
_a
517.95 OLE
999
_c
3838
_d
3838