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)
Wijewardhana, W.G.L.P.; Edirisinghe, J.; Auwardt, D.M.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2006)