LIVER AND KIDNEY NITROGEN UPTAKE IN RATS FED BEANS ENRICHED WITH N-15 THROUGH ((NH4)2SO4)-N-15 USED AS SOIL FERTILIZER - Marchini, J. S.; Matsui, E.; Souza, N.; Dutradeoliveira, J. E. (Associação Brasileira de Divulgação Científica (ABRADIC), 1990)