Samaraweera, S.P.D.P.; Jayasinghe, J.M.U.K.; Gangoda, U.E.K.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)
Perera, B.S.P.S.S.; Fernandopulle, M.N.D.; Sherath, C.S.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)
Ariyarathne, G.S.D.P.C.; Gajanayake, K.G.M.C.P.B.; Jayasinghe-Mudalige, U.K.; Senaweera, L.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2006)