Nummer, Andrea, Guareschi, Vinícius, AND Sangói, Dionísio. " A FRAGILIDADE AMBIENTAL DO AQUÍFERO SERRA GERAL NA SUB-BACIA HIDROGRÁFICA DO ALTO URUGUAI-BRASIL (the environmental fragility in Serra Seral aquifer in Alto Uruguai hydrographic basin in Brazil)" Mercator [Online], Volume 10 Number 23 (21 November 2011)