Elschner, J <br/><br/>
Singular ordinary differential operators & pseudodifferential equations 
J. Elschner 
 - Berlin  Springer  1985 
 - 200 
 - Lecture notes in mathematics 1128 .
<br/><br/><label>ISBN: </label>354015194x 
<br/><br/><label>Dewey Class. No.: </label>10.07+22  / ELSC