TY  - BOOK
AU  - Elsgolts,L.E.
TI  - Differential equations and the calculus of variations
PY  - 1970///
CY  - Moscow
PB  - Mir
KW  - Differential equations
KW  - Calculus of variations
N1  - Translation of Differentsialnye uravneniia i variatsionnoe ischislenie; Bibliography: p. 436
ER  -