Dacorogna, B. <br/><br/>
Direct methods in the calculus of variations  / 

 - Berlin:  Springer-Verlag,  1989 
 - ix, 308p. Index. Bibl. 
 - Applied Mathematical Sciences    v. 78 .
<br/><br/><label>Dewey Class. No.: </label>515.64  / D118.DM