Edirisinghe, D.P.D.S.; Athauda, A.M.T.P.; Yapa, G.B.; Jayawardana, C.P.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)
Bandara, D.R.S.S.; Athauda, A.M.T.P.; Randeniya, R.M.R.; Rathnayake, R.D.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2006)