TY  - BOOK
AU  - Sagan,Hans
TI  - Introduction to the calculus of variations
T2  - International series in pure and applied mathematics
AV  - QA315 .S23
U1  - 517/.4 
PY  - 1969///]
CY  - New York
PB  - McGraw-Hill
KW  - Calculus of variations
N1  - Bibliography: p. 434-437
ER  -