Ranasinghe, B.M.C.M.; Sumanasena, H.A.; Amarakoon, A.M.E.S.; Lakmali, W.A.S.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2013)
Basnayake, B.M.S.; Fernandopulle, M.N.D.; Sumanasena, H.A.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)