Perera, S.A.S.P.; Vithana, M.D.K.; Jayasekera, S.J.B.A.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2013)
Kumari, G.G.S.; Kumari, S.A.S.M.; Vithana, M.D.K.; Mannanayake, M.A.D.K.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2013)