ChemGlobe: Samarium: Electronic, thermal, and steric data along with an isotope table.
ChemicalElements.com: Samarium: Basic information, atomic structure, and isotopes table.
EnvironmentalChemistry.com: Samarium: Atomic structure, chemical and physical properties, and table of nuclides.
It's Elemental: Samarium: Basic physical and historical information.
LANL: Samarium: Sources, properties, isotopes, and uses.
Lenntech: Samarium: Physical data, chemical properties, health and environmental effects.
Samarium: Data tables and historic information.
Visual Elements: Samarium: Image, source, uses, physical information, and key isotopes.
WebElements: Samarium: Extensive information on history, uses, occurrence, compounds, and properties.
Wikipedia: Samarium: Properties of the element, including its history, applications, and characteristics.