Lankford, Francis Greenfield, 1906- <br/><br/>
Numbers and operations/ 
/ by F.G. Lankford, D. D. Hiekkinen and I. M. Silvey. 
 - New York:  Harcourt,  1970. 
 - 461 p. :   ill. ;   22 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Numeration.<br/> Mathematics.