GeoRef This link opens in a new window1785-
GeoRef, produced by the American Geological Institute, indexes the world's literature in geology and the geosciences. Its over 1.7 million citations, many with abstracts, cover the geology of North America since 1785 and the geology of the rest of the world since 1933. It scans over 3,000 journals in 40 languages as well as books, maps, and reports. Most U.S. Geological Survey publications and many state geological surveys are indexed, as are U.S. and Canadian theses and dissertations.