Basic information, atomic structure, and isotopes.
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 J. Pijck (Laboratory for Analytical Chemistry, University of Ghent, G...
Extensive information on history, uses, occurrence, compounds, and properties of the element.