Gleen, William H. <br/><br/>
Number patterns / 
William H. Gleen [and] Donovan A. Johnson 
 - London :  John Murray,  [n.d.] 
 - 47 p. ;  22 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Arithmetic
<br/><br/><label>Dewey Class. No.: </label>511.2