Abedeera , Nilmini ජ්යාමිතිය : - Samudara : Colombo ; 2023. - 227 p ; 21 cm . 01 - 2025-01-06 ISBN: 9786242032184 Nat. Bib. No.: 0011039 Nat. Bib. Agency Control No.: ABE Universal Decimal Class. No.: 510