Lefschetz, S,  <br/><br/>
Contributions to the theory of nonlinear oscillations, Vol.3 
S Lefschetz  
 - 
 - Princeton University Press, New Jersey  1956 
 - 
 - Annals of Mathematics Studies, Vol.036 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Annals of Mathematics Studies
<br/><br/><label>Dewey Class. No.: </label>R  AMS.036