Tennakoon, M.S.B.W.T.M.N.S.; Attanayaka, D.P.S.T.G.; Mahendra, R.A.R.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2016)
Deepika, U.K.D.K.; Senevirathne, P.; Nayanakantha, C.; Wickramasinghe, W.M.E.P.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)