Egorov, Yuri and Kondratiev, Vladimir <br/><br/>
On spectral theory of elliptic operators   

 - Basel  Birkhauser Verlag  1996 
 - x, 328p. Index, Bibl. 
 - Operator theory  advances and applications ; v. 89 .
<br/><br/>  
<br/><br/><label>Dewey Class. No.: </label>515.72  / Eg31.OS