ChemGlobe: Chromium - - Electronic, thermal, and steric data along with an isotopes table.

ChemicalElements.com: Chromium - - Basic information, atomic structure, and isotopes.

EnvironmentalChemistry.com: Chromium - - Atomic structure, chemical and physical properties, and table of nuclides.

It's Elemental: Chromium - - Basic physical and historical information.

LANL: Chromium - - History, sources, uses, and compounds.

Lenntech: Chromium - - Physical data, chemical properties, health and environmental effects.

USGS Minerals Information: Chromium - - Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).

Visual Elements: Chromium - - General and physical information, source, uses, key isotopes, and ionisation energies.

WebElements: Chromium - - Extensive information on history, uses, occurrence, compounds, and properties of the element.

Wikipedia: Chromium - - Properties of the element, including its history, applications, and characteristics.

Radiochemistry of Chromium - - Full text of the monograph by J. Pijck (Laboratory for Analytical Chemistry, University of Ghent, Ghent, Belgium). [PDF] (December, 1964)