Guy, Richard K. <br/><br/>
Unsolved problems in number theory   

 - New York  Springer-Verlag  1981 
 - xviii, 161p. Index 
 - Problem books in Mathematics .
<br/><br/> "Lib. also has 2nd edn. (1994)"   
<br/><br/><label>ISBN: </label>0387942890 
<br/><br/><label>Dewey Class. No.: </label>512.7  / G986.UP