Andreescu, Titu <br/><br/>
Quadratic diophantine equations / 

 - New York:  Springer,  2015 
 - xviii, 211p. Bibl. Index 
<br/><br/><label>ISBN: </label>9780387351568 
<br/><br/><label>Dewey Class. No.: </label>512.72  / An558.QD