It's Elemental: Selenium - Basic physical and historical information. ChemicalElements.com: Selenium - Basic information, atomic structure, and isotopes. USGS Minerals Information: Selenium - Statistics and information on the worldwide supply, demand, and flow of the element (PDF format). EnvironmentalChemistry.com: Selenium - Atomic structure, chemical and physical properties, and table of nuclides. 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). Linking Selenium Sources to Ecosystems: Local and Global Perspectives - U.S. Geological Survey materials on the environmental sources, biogeochemistry, and toxicology of selenium. WebElements: Selenium - Extensive information on history, uses, occurrence, compounds, and properties of the element.