ChemGlobe: Vanadium - Electronic, thermal, and steric data along with an isotope table. - http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/23.html
LANL: Vanadium - History, sources, uses, and properties. - http://periodic.lanl.gov/elements/23.html
Wikipedia: Vanadium - Properties of the element, including its history, applications, and characteristics. - http://en.wikipedia.org/wiki/Vanadium
Lenntech: Vanadium - Physical data, chemical properties, health and environmental effects. - http://www.lenntech.com/Periodic-chart-elements/V-en.htm
EnvironmentalChemistry.com: Vanadium - Atomic structure, chemical and physical properties, and table of nuclides. - http://environmentalchemistry.com/yogi/periodic/V.html
Visual Elements: Vanadium - General and physical information, source, uses, key isotopes, and ionisation energies. - http://www.chemsoc.org/viselements/pages/vanadium.html
USGS Minerals Information: Vanadium - Statistics and information on the worldwide supply, demand, and flow of the element (PDF format). - http://minerals.usgs.gov/minerals/pubs/commodity/vanadium/
Radiochemistry of Vanadium - Full text of the monograph by J. L. Brownlee Jr. (Dept. of Chemistry, University of Michigan, Ann Arbor, Michigan). [PDF] - http://lib-www.lanl.gov/cgi-bin/getfile?rc000005.pdf