Dutram ,Hilda <br/><br/>
Dinamina supaShathraya 

 - Colombo  Lake House  1999 
 - xxiii,314,xvi p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>TECHNOLOGY
<br/><br/><label>Universal Decimal Class. No.: </label>641.5  / DUT