Palliyaguru, S.J.; Gunarathne, G.P.; Abeysinghe, D.C.; Fernandopulle, M.N.D.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2013)
Jayasuriya, S.H.P.; Gajanayake, K.G.M.C.P.B.; Abeysinghe, D.C.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)