Pontriagin L S <br/><br/>
Ordinary differential equations 
Pontriagin L S 
 - Delhi  Hindustan Publishing House          1967 
 - x, 333p  cm. 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Dewey Class. No.: </label>B331, K7/TD3