Friedman, Avner. <br/><br/>
Variational principles and free-boundary problems / 
Avner Friedman. 
 - New York :  Wiley,  1982. 
 - 710p. ;  25 cm. 
 - Pure and applied mathematics. .
<br/><br/> 'A Wiley-Interscience publication.'. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Boundary value problems.<br/>Variational principles.