Dharmarathna, K.P.D.U.; Jayasinghe-Mudalige, U.K.; Silva, K.D.R.R.; Chandrasekara, G.A.P.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2006)
Kumari, R.M.P.D.; Gajanayake, K.G.M.C.P.B.; Chandrasekara, G.A.P.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)