Guy, Richard K. <br/><br/>
Unsolved problems in number theory / 
Richard K. Guy 
 - 2nd ed. 
 - New York :  Springer-Verlag,  1994 
 - 285 p. :  ill. ;  25 cm. 
 - Problem books in mathematics .
<br/><br/><label>ISBN: </label>0387942890  RM124.20 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Number theory