Berard, P.H <br/><br/>
Spectral geometry  direct & inverse problems 
P.H. Berard 
 - Berlin  Springer  1986 
 - xiii  272 
 - Lecture notes in mathematics 1207 .
<br/><br/><label>ISBN: </label>3540167889 
<br/><br/><label>Dewey Class. No.: </label>10.06  / BERA