Polya, G. <br/><br/>
How to solve it  a new aspect of mathematical method 
by G. Polya 
 - 2nd. 
 - Princeton  Princeton Univ.Press  1957 
 - xxi, 253p. 
<br/><br/><label>ISBN: </label>0691080976 
<br/><br/><label>LCCN: </label>79-160544 
<br/><br/><label>Dewey Class. No.: </label>510  / N574