Perera, Lal විස්තරාත්මක අධ්යාපනික සංඛ්යානය = Wistharaathmaka Adhyaapanika Sankhyaanaya - Kottawa: Sara Publisher, 1991. - 160p.; 21cm Subjects--Topical Terms: Probabilities and applied mathematics Dewey Class. No.: 519.5 / PER