Natural radiocarbon measurements in Brazilian soils developed on basic rocks - Pessenda, Luiz Carlos Ruiz; Valencia, E. P. E; Camargo, Plinio Barbosa de; Telles, E. C. C; Martinelli, Luiz Antonio; Cerri, Carlos Clemente; Aravena, Ramon; Rozanski, Kazimierz (Radiocarbon, 1996)