Griffiths, Phillip A. <br/><br/>
Exterior differential systems and the calculus of variations / 
Phillip A. Griffiths 
 - Boston, MA. :  Birkhauser,  1983 
 - 335 p. ;  23 cm. 
 - Progress in mathematics ;  v. 25 .
<br/><br/>Includes bibliographical references and index 
<br/><br/><label>ISBN: </label>3764331038 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Calculus of variations<br/>Exterior differential systems