SciFinder [Registration Required] [via American Chemical Society]
SciFinder is the most comprehensive bibliographic database for scholarly research in the field of chemistry. It contains over 52 million citations and indexes over 50,000 journals, covering all aspects of chemistry, including chemical aspects of: biology and life sciences, engineering and materials science, food science, geology, medicine, physics, and polymer science. SciFinder also allows searching of chemical substances, chemical reactions, and includes some property data and spectra.
1907-present (with selected pre-1907 material)