Basic information, atomic structure, and isotopes table.
Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).
Atomic structure, chemical and physical properties, and table of nuclides.
Properties of the element, including its history, applications, and characteristics.
Full text of the monograph by M. T. Kinsley (Brookhaven National Laboratory, Upton, New York).
Extensive information on history, uses, occurrence, compounds, and properties.