00581nam a2200193Ia 4500082001900000100002500019245006000044260004900104300000600153490004000159500000500199690000600204700000500210952010100215964001700316965002700333921001000360999001700370  a530.1bL495.CT  aLefschetz, S. d ed.  aContributions to the theory of nonlinear oscillationsb  aNew JerseybPrinceton University Pressc1958  a   aAnnals of Mathematics studies v 41  a  a   a  00104070aISIbISId1998-10-09l0o530.1 L495.CTpDP15161r2019-02-14 00:00:00w2019-02-14yBK  abcdefg  aLib. has:- v. 4, 211p.  a16421  c16421d16421