Lavrent'ev, M.A <br/><br/>
Variational methods for boundary value problems for systems of elliptic equations 

 - New York  Dover Publications, Inc  1989 
 - 153p.  HB  22cm. 
<br/><br/><label>ISBN: </label>9780486450780 
<br/><br/><label>Dewey Class. No.: </label>515.3523  / LAV