Gelfand, I M <br/><br/>
Calculus of Variations 
by I M Gelfand and S V Fomin 
 - Mineola  Dover  1991 
 - vii, 232p. 
<br/><br/><label>ISBN: </label>9780486414485 
<br/><br/><label>Dewey Class. No.: </label>515.64  / P;1 (ECE)