Shashikala, S.D.A.; Gayeshani, E.A.K.; Navodya, L.M.G.; Rathnamalala, R.B.I.V.; Dilini, A.M.
(5th National Conference on Applied Social Statistics (NRCASS) - 2019, Department of Social Statistics, Faculty of Social Sciences, University of Kelaniya, Sri Lanka, 2019)