ChemGlobe: Rhodium
   Electronic, thermal, and steric data along with an isotope table.
   http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/45.html

ChemicalElements.com: Rhodium
   Basic information, atomic structure, and isotopes.
   http://www.chemicalelements.com/elements/rh.html

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

It's Elemental: Rhodium
   Basic physical and historical information.
   http://education.jlab.org/itselemental/ele045.html

LANL: Rhodium
   History, sources, properties, and uses.
   http://periodic.lanl.gov/elements/45.html

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

Radiochemistry of Rhodium
   Full text of the monograph by James Armstrong (Florida State University, Tallahassee, Florida). [PDF]
   http://lib-www.lanl.gov/cgi-bin/getfile?rc000063.pdf

Visual Elements: Rhodium
   General and physical information, source, uses, key isotopes, and ionisation energies.
   http://www.chemsoc.org/viselements/pages/rhodium.html

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