Goonawardane Kanthi <br/><br/>
SCIENCE & TECHNOLOGY 

 - 2nd Ed 
 - Nugegoda  Sarasavi Publishers,  2005. 
 - 82 pag 
<br/><br/><label>ISBN: </label>9555732876 
<br/><br/><label>Dewey Class. No.: </label>600  / 425