TY  - BOOK
AU  - L Ė Ėlʹsgolʹt︠s︡
AU  - L Ė Ėlʹsgolʹt︠s︡
TI  - ifferential equations and the calculus of variations
U1  - 515.35 ELS 
PY  - 1970///
CY  - Moscow, 
PB  - :Mir Publishers
KW  - Mathematics
KW  - ;Differential equations
KW  - ;Calculus of variations
ER  -