Gunaratna, Ranga රසායන විද්යාව:අ.පො.ස උසස් පෙළ = rasayana widyawa:a.po.sa usas pela - Padukka: Author, 2008. - 217p.; 23cm ISBN: 9551626044 Subjects--Topical Terms: Chemistry & allied sciences Dewey Class. No.: 540 / GUN