TY  - DATA
AU  - A. Ambrosetti, V. Coti-Zelati
TI  - Periodic Solutions of Singular Lagrangian Systems
SN  - 9781461203193
PY  - 1993///
PB  - Birkhäuser Boston
KW  - Mathematics and Statistics
UR  - https://doi.org/10.1007/978-1-4612-0319-3
ER  -