Mihindukulasuriya, R.H.; Dassanayake, E.M.; Perera, W.G.S.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2006)
Jayaweera, S.L.D.; Basnayake, B.M.V.S.; Dassanayake, E.M.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)