1. GeoRef was established by the American Geological Institute (AGI) in 1966, providing access to the geoscience literature of the world. It is the most comprehensive AGI database in the geosciences and continues to grow by more than 100,000 references a year.
2. The Lyell Collection created to mark the Geological Society of London's 200th anniversary in 2007, represents one of the largest integrated collections of online Earth science literature available. Bringing together key journals, Special Publications and Society book series on a single electronic platform.
3. Scopus is a broadly based database: good for interdisciplinary subjects, searching for authors and tracking down citations. Its interface is flexible and easy to use.
4. Web of Science also provides broad coverage and good author and citation searching. It includes Science Citation Index, Index to Conference Proceedings and Journal Citation Reports.