Ball, W. W. Rouse <br/><br/>
Mathematical recreations & essays 
by W. W. Rouse Ball. 
 - Revised ed. 
 - London  The MacMillan Company  1940. 
 - xvi, 418 p., 1 l.  illus., diagrs. 
<br/><br/>Includes bibliographical footnotes and index. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematical recreations.<br/>Ciphers.<br/>Cryptography.<br/>Geometry--Problems, Famous.