Coddington, Earl A.,  1920- <br/><br/>
Regular boundary value problems associated with pairs of ordinary differential expressions / 
Earl A.Coddington Hendrik S.V.de Snoo 
 - Berlin :  Springer-Verlag,  1981 
 - 225 p. ;  24 cm. 
 - Lecture notes in mathematics  858 .
<br/><br/>Bibliography: p. 220-223 Includes index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Boundary value problems<br/>Differential operators<br/>Eigenfuction expansions