000			003300000a22001450004500
001			EST
003			551.1 / R31
004			M
006			m
100			_aRichards, L. W.
100			_aRichards, G. L.
245			_aGeologic history at a glance
650			_a<GEOLOGIA><ERAS GEOLOGICAS><ESTRUCTURA DE LA TIERRA>
999			_c18003 _d18003