Notes on the shifting course of the ancient Rio Orinoco from Late Cretaceous to Oligocene time. Emile Rod, 1981. GEOS, Número 81, pp. 30 – 31, 1981. You can download complete PDF version at / Puedes bajar la versión completa en PDF en: https://mariantoc.github.io/stratigraphy.html#RodE1981