GeoRef is the most comprehensive AGI database in the geosciences and continues to grow by more than 100,000 references a year. The database contains over 3 million references to geoscience journal articles, books, maps, conference papers, reports and theses. The GeoRef database covers the geology of North America from 1669 to the present and the geology of the rest of the world from 1933 to the present. The database includes references to all publications of the U.S. Geological Survey.