Gardner, Martin,  1914- <br/><br/>
Knotted doughnuts and other mathematical entertainments / 
Martin Gardner. 
 - New York :  W.H. Freeman,  c1986. 
 - xii, 278 p. :  ill. 
<br/><br/><label>ISBN: </label>0716717999 (pbk.) 0716717948 (hard) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematical recreations.
<br/><br/><label>Dewey Class. No.: </label>793.7/4�19