Northrop, Eugene P. <br/><br/>
Riddles in mathematics 

 - Harmondsworth  Penguin Books  1960 
 - 239 
 - Pelican Books A 478 .
<br/><br/> With appendix & references 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Arithmatic<br/>Geometry<br/>Mathematics<br/>Mathematics
<br/><br/><label>Dewey Class. No.: </label>510  / N818r