නිබන්ධන පොත 
 Tutorials book 

 -  Abacus computer institute ltd  1996 
 - 500p.,  26 cm 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Abacus
<br/><br/><label>Universal Decimal Class. No.: </label>681.31  / NIB