Thilakarathne, K. M. D. M.; Ubesekara, K.K.S.U.I.; Udayanganee, K.G.L.; Wijeesingha, W.M.W.M.; Weerasinghe, R.D.S.K.
(5th National Conference on Applied Social Statistics (NRCASS) - 2019, Department of Social Statistics, Faculty of Social Sciences, University of Kelaniya, Sri Lanka, 2019)