Asimov , Isaac දෙවන පදනම : - S & T Group : Koswaththa ; 2023. - 223 p; 21 cm . 01 - 2024-10-24 ISBN: 9786245712144 Nat. Bib. No.: 0010920 Nat. Bib. Agency Control No.: ASI Universal Decimal Class. No.: 891.483