ChemGlobe: Molybdenum
   Electronic, thermal, and steric data along with an isotope table.
   http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/42.html

ChemicalElements.com: Molybdenum
   Basic information, atomic structure, and table of isotopes.
   http://www.chemicalelements.com/elements/mo.html

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

It's Elemental: Molybdenum
   Basic physical and historical information.
   http://education.jlab.org/itselemental/ele042.html

LANL: Molybdenum
   History, sources, uses, and properties.
   http://periodic.lanl.gov/elements/42.html

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

Radiochemistry of Molybdenum
   Full text of the monograph by E. M. Scadden (U.S. Naval Radiological Defense Laboratory, San Francisco, California). [PDF]
   http://lib-www.lanl.gov/cgi-bin/getfile?rc000069.pdf

USGS Minerals Information: Molybdenum
   Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).
   http://minerals.usgs.gov/minerals/pubs/commodity/molybdenum/

Visual Elements: Molybdenum
   Image, general and physical information, source, uses, key isotopes, and ionisation energies.
   http://www.chemsoc.org/viselements/pages/molybdenum.html

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