The calculus of variations // 
Bruce van Brunt. 
 - New York ::  Springer,  c2004. 
 - xiii, 290 p. : 
<br/><br/><label>ISBN: </label>0387402470 (alk. paper) 
<br/><br/><label>Dewey Class. No.: </label>515.64  / BRU/C