Rellich, Franz <br/><br/>
Spectral theory of a second-order ordinary differential operator/ 
by Franz Rellich ; with an appendix by K. O. Friedrichs ; notes by J. Berkowitz. 
 - New York:  [New York University Press],  1953. 
 - iii, 159 p. ;  28 cm. 
<br/><br/> At head of title: New York University, Institute of Mathematical Sciences.  "Lectures delivered 1950-1951." 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Spectral theory (Mathematics).<br/>Differential operators.<br/>Boundary value problems.
<br/><br/><label>Dewey Class. No.: </label>515.35  / R383s