Ruthenium

ChemGlobe: Ruthenium - Electronic, thermal, and steric data along with an isotope table.
partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/44.html

ChemicalElements.com: Ruthenium - Basic information, atomic structure, and table of isotopes.
www.chemicalelements.com/elements/ru.html

EnvironmentalChemistry.com: Ruthenium - Atomic structure, chemical and physical properties, and table of nuclides.
environmentalchemistry.com/yogi/periodic/Ru.html

It's Elemental: Ruthenium - Basic physical and historical information.
education.jlab.org/itselemental/ele044.html

LANL: Ruthenium - History, sources, uses, and properties.
periodic.lanl.gov/elements/44.html

Lenntech: Ruthenium - Physical data, chemical properties, and health effects.
www.lenntech.com/Periodic-chart-elements/Ru-en.htm

Visual Elements: Ruthenium - Image, discovery, uses, source, and physical information.
www.chemsoc.org/viselements/pages/ruthenium.html

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