Sampath, V.P.S.; Zuhry, A.L.M.; Weerakkody, W.J.S.K.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2013)
Jayasundara, J.M.D.M.; Ranundeniya, R.M.N.S.; Lakmali, W.A.S.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2016)