"Merttens Ruth" <br/><br/>
Abacus evolve Textbook No. 3 

 - LAHORE  ,Ginn & Company  2001 
 - 80 
<br/><br/><label>ISBN: </label>9780602575168 
<br/><br/><label>Dewey Class. No.: </label>510  / 433-T