TY  - BOOK
AU  - Gelfand, I M
AU  - Fomin, S V
TI  - Calculus of variations
SN  - 9780486414485
CY  - New York
KW  - Calculus -- Variations
KW  - Euler equations -- Canonical form
KW  - Mathematics
KW  - Variational problems
N1  - Includes bibliographical references and index
ER  -