Lefschetz, Solomon,  1884-1972 <br/><br/>
Contributions to the theory of nonlinear oscillations  / 
[by] S. lefschetz, S.P. Diliberto. 
 - Princeton, N.J. :  Princeton University Press,  1952. 
 - 2v. :  ill., diagrs. ;  23 cm. 
 - Annals of mathematics studies ;  no. 20, 29. .
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Oscillations.