Wallis W D <br/><br/>
Magic graphs / 
W.D. Wallis. 
 - Boston :  Birkh 
<br/><br/><label>ISBN: </label>0817642528 (acid-free paper) 3764342528 (acid-free paper) 
<br/><br/><label>LC Class. No.: </label>QA166.197 
<br/><br/><label>Dewey Class. No.: </label>511/.5