Weragoda, Ravindhra රසායන විද්යාව 11 ශ්රේණීය - S.Godage Publisher Colombo 2009 - 116p 1 - 2024-02-05 ISBN: 978-955-30-2215-8 Nat. Bib. No.: 0002523 Nat. Bib. Agency Control No.: WER Universal Decimal Class. No.: 540