Lefschetz, Solomon,  1884-1972, <br/><br/>
Contributions to the theory of nonlinear oscillations / 
by S. P. Diliberto [and others] 
 - volúmenes 
 - Annals of mathematics studies ;  20, 29, 36, 41, 45 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Oscilaciones
<br/><br/><label>LC Class. No.: </label>QA871  / L44