Index of articles from over 10,000 journals in the sciences, social sciences, arts, and humanities. In addition to multidisciplinary searches, Web of Science provides tools to track citations to individual articles from their date of publication to the present. Now includes Book Citation Index and Conference Proceedings Citation Index. Coverage: 1984-present.
Index of journal articles, books, maps, conference papers, reports, and theses covering the geology of North America from 1785 to the present and the geology of the rest of the world from 1933 to the present. Includes references to all publications of the U.S. Geological Survey. Coverage: 1785-present.
The complete archive of National Geographic magazine — every page of every issue — along with a cross-searchable collection of National Geographic books, maps, images and videos. Coverage: 1888 to present.
Over 600 images can be downloaded for educational use.