Sri Lanka association for the advancement of science 

 - Colombo  Vidya mandiraya  1989 
 - xiii, 143 p. 
<br/><br/><label>ISBN: </label>167487 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science
<br/><br/><label>Dewey Class. No.: </label>500  / SRI