Jayasena, M.K.A.S.; Iqbal, M.C.M.; Attanayaka, D.P.S.T.G.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)
Rankothge, D.G.D.C.; Kumari, H.M.P.S.; Perera, P.I.P.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2016)