TY  - BOOK
AU  - Elsgolts L
AU  - Yankovsky George
TI  - Differential equations and the calculus of variations
U1  - 515.35 
PY  - 1977///
CY  - Moscow
PB  - Mir Pubs
KW  - Calculus
KW  - Differential equations
N1  - Tr from Russian
ER  -