Devasinghe, D.M.A. <br/><br/>
Grade - 07 Science & Technology :  A Supplimentary Text Book. 

 - 1st, Ed. 
 - Colombo :  S&S Printers, 
 - 153 p. 
<br/><br/><label>ISBN: </label>955980801x 
<br/><br/><label>Dewey Class. No.: </label>500  / DEV