Selenium Watch - Information resource on adverse health and environmental effects from increased use of selenium by industry, maintained by a non-profit consortium of scientists, researchers and engineers.
Visual Elements: Selenium - Image, general and physical information, source, uses, key isotopes, and ionisation energies.
WebElements: Selenium - Extensive information on history, uses, occurrence, compounds, and properties of the element.
Wikipedia: Selenium - Properties of the element, including its history, applications, and characteristics.
Radiochemistry of Selenium - Full text of the monograph by V. J. Molinski (Union Carbide Corporation, Mining and Metals Division, Research Center, Tuxedo, New York) and G. W. Leddicotte (Oak Ridge National Laboratory, Oak Ridge, Tennessee). [PDF] (November, 1965)