Arthurs, A. M. <br/><br/>
Complementary variational principles   

 - 2nd. 
 - Oxford  Clarendon Press  1980 
 - vii, 154p. Index 
 - Oxford Mathematical monographs .
<br/><br/>  
<br/><br/><label>Dewey Class. No.: </label>515.64  / Ar791.CV