Number system  
Thurston, H. A. 
 - Dover ed. 
 - Mineola, N.Y. :  Dover Publications,  2007 
 - viii, 134 p. :  ill. ;  22 cm. 
<br/><br/> Originally published: London : Blackie and Son ; New York : Interscience Publishers, 1956. | Includes index. 
<br/><br/><label>ISBN: </label>0486458067 (pbk.) | 9780486458069 (pbk.)