Rathnayake, R.M.C.P.; Perera, W.G.S.; Dassanayake, E.M.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2006)
Rangana, S.H.C.S.; Basnayake, B.M.V.S.; Perera, W.G.S.; Dassanayake, E.M.(Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, 2005)
Subasinghe, S.A.M.S.; Abeynayake, N.R.; Shyamale, H.W.; Wellala, N.N.K.(Faculty of Agriculture and Plantation Management,Wayamba University of Sri Lanka, Makandura, 2013)
Pathirawasam, C.; Weerakoonbanda, Y.K.(Department of Business Management, Faculty of Business Studies and Finance, Wayamba University of Sri Lanka. Kuliyapitiya, 2010)