Rosa, B. and Fichtner, S.S. (2007) “EVALUATION OF THE OXALIC ACID CONTENT OF ANDROPOGON GRASS (Andropogon gayanus var. bisquamulatus cv. Planaltina) AT DIFFERENT CUTTING AGES”, Pesquisa Agropecuária Tropical [Agricultural Research in the Tropics], 23(1), pp. 119–127. doi:10.5216/pat.v23i1.2635.