Uhl, C., Barreto, P., Veríssimo, A., Vidal, E., Amaral, P., Barros, A. C., Souza Jr., C., Johns, J. & Gerwing, J., 1997. Leia também:The regional impacts of small-scale gold mining in Amazonia.Ranching in the Brazilian Amazon in a national context: economics, policy and practice.