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Alva Valdivia, L. M.; Rosales, M. C.; Benammi, M.; Grajales Nishimura, M.; Gogitchaichvili, A.; Urrutia Fucugauchi, J. Reconnaissance Microfossil and Magnetic Stratigraphy of the Miocene Sayula-Isla Sequence, Veracruz, Mexico. Geofis Int 2002, 41, 151-161.