Phanthavong V, Sangkhom I, Preston T R, Dung D V and Ba N X 2018: Effect of leaves from sweet or bitter cassava and brewers’ grains on methane production in an in vitro rumen incubation of cassava root pulp-urea. Livestock Research for Rural Development. Volume 30, Article #167. Retrieved , from http://www.lrrd.org/lrrd30/9/phant30167.html