Calculus of Variations /  
Gelfund I. M. ; Fomin S.V. 
 - Mineola, New York :   Dover Publications ,   2000 
 - vii , 232 p.  22cm. 
<br/><br/><label>ISBN: </label>0486414485 
<br/><br/><label>LC Class. No.: </label>QA315  / .G44  2000