Use of carbon isotopes in palaeoenvironmental studies in Brazil - Pessenda, Luiz Carlos Ruiz; Valencia, E P E; Camargo, Plinio Barbosa de; Martinelli, Luiz Antonio; Telles, E C C; Cerri, Carlos Clemente (International Symposium on Applications of Isotope Techniques in Studying Past and Current Environmental Changes in the Hydrosphere and the Atmosfere, 1993)