The Petaca (late Oligocene-Middle Miocene) and Yecua (late Miocene) formations of the subandean-Chaco basin, Bolivia, and their tectonic significance Marshall, L.G. /Sempéré, Thierry Gayet, M. TECTONIQUE MIOCENE DATATION CONGLOMERAT FOSSILE MILIEU MARIN SEDIMENT 1993 text https://www.documentation.ird.fr/hor/fdi:010024184 fdi:010024184 Marshall L.G., Sempéré Thierry, Gayet M.. The Petaca (late Oligocene-Middle Miocene) and Yecua (late Miocene) formations of the subandean-Chaco basin, Bolivia, and their tectonic significance. 1993, 291-300 multigr. EN BOLIVIE