Samarium

ChemGlobe: Samarium
Electronic, thermal, and steric data along with an isotope table.
http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/62.html

ChemicalElements.com: Samarium
Basic information, atomic structure, and isotopes table.
http://www.chemicalelements.com/elements/sm.html

EnvironmentalChemistry.com: Samarium
Atomic structure, chemical and physical properties, and table of nuclides.
http://environmentalchemistry.com/yogi/periodic/Sm.html

It's Elemental: Samarium
Basic physical and historical information.
http://education.jlab.org/itselemental/ele062.html

LANL: Samarium
Sources, properties, isotopes, and uses.
http://periodic.lanl.gov/elements/62.html

Lenntech: Samarium
Physical data, chemical properties, health and environmental effects.
http://www.lenntech.com/Periodic-chart-elements/Sm-en.htm

Visual Elements: Samarium
Image, source, uses, physical information, and key isotopes.
http://www.chemsoc.org/viselements/pages/samarium.html

WebElements: Samarium
Extensive information on history, uses, occurrence, compounds, and properties.
http://www.webelements.com/webelements/elements/text/Sm/key.html

Wikipedia: Samarium
Properties of the element, including its history, applications, and characteristics.
http://en.wikipedia.org/wiki/Samarium