000			00495nmm a2200145Ia 4500
008			230125s9999||||xx |||||||||||||||||und||
020			_a9781461203193
100			_aA. Ambrosetti, V. Coti-Zelati
245		0	_aPeriodic Solutions of Singular Lagrangian Systems
250			_a1993
260			_bBirkhäuser Boston _c1993
440			_aProgress in Nonlinear Differential Equations and Their Applications
650			_aMathematics and Statistics
856			_uhttps://doi.org/10.1007/978-1-4612-0319-3
999			_c7734 _d7734