Guy, Richard K. <br/><br/>
Unsolved problems in number theory / 
​ Richard K. Guy. 
 - New York :  Springer-Verlag,  c1981. 
 - xviii, 161 p. :  ill. ;  24 cm. 
 - Problem books in mathematics. .
 - Unsolved problems in intuitive mathematics ;  ; v. 1. .
 - Guy, Richard K ;  Unsolved problems in intuitive mathematics.  v. 1. .
<br/><br/>Includes bibliographies and indexes. 
<br/><br/><label>ISBN: </label>0387905936 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Number theory--Problems, exercises, etc.