Ruwanpura, Thilak ප්රස්තාර : 9,10,11 ශ්රේණි සදහා = prasthaara 9,10,11 - Colombo : Sadeepa Prakashana, 1999. - 151p.; 22cm ISBN: 955-9374-41-9 Subjects--Topical Terms: MathematicsEducation Dewey Class. No.: 510 / RUW