Schechter, Martin <br/><br/>
Spectra of partial differential operators   

 - Amsterdam  North-Holland  1971 
 - xiii, 267p. Index, Bibl. 
 - North-Holland series in Applied Mathematics and mechanics   v. 14 .
<br/><br/>  
<br/><br/><label>Dewey Class. No.: </label>515.35  / Sc314.SP