Lefschetz, Solomon.  <br/><br/>
Contributions to the theory of nonlinear oscillations.   Volume II. 

 - Princeton :   Princeton University Press,   1952. 
 - 116 p. 
 - Annals of mathematics studies.   Number 29 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>VIBRACIONES<br/>ACUSTICA<br/>VIBRACIONES MECANICAS
<br/><br/><label>Universal Decimal Class. No.: </label>531.14