Visual Elements: Manganese - General and physical information, source, uses, biological role, key isotopes, and ionisation energies.
WebElements: Manganese - Extensive information on history, uses, occurrence, compounds, and properties of the element.
Wikipedia: Manganese - Properties of the element, including its history, applications, and characteristics.
Radiochemistry of Manganese - Full text of the monograph by R. P. Schuman (Dept. of Chemistry, Robert College, Bebek P.K.8, Istanbul, Turkey). [PDF] (July, 1971)