ChemicalElements.com: Terbium
Basic information, atomic structure, and isotopes.
EnvironmentalChemistry.com: Terbium
Atomic structure, chemical and physical properties, and table of nuclides.
It's Elemental: Terbium
Provides information on history and properties.
Lenntech: Terbium
Physical data, chemical properties, health and environmental effects.
Visual Elements: Terbium
Image, source, physical information, and key isotopes.
WebElements: Terbium
Extensive information on history, uses, occurrence, compounds, and properties.
Wikipedia: Terbium
Properties of the element, including its history, applications, and characteristics.