Coddington, E. A. and Snoo, Hendrik S. V. de. <br/><br/>
Regular boundary value problems associated with Paris of ordinary differential expressions   

 - Berlin  Springer-Verlag  1981 
 - 225p. Index 
 - Lecture notes in Mathematics   858 .
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<br/><br/><label>Dewey Class. No.: </label>515.35  / C669.RB