Pontryagin L.S. <br/><br/>
Ordinary differential equations. 
Pontryagin L.S. 
 - Massachustts  Addison Wesley Publishing Company Inc.        1962 
 - vi,298p.  cm. 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Dewey Class. No.: </label>B331, K2;5