ChemGlobe: Einsteinium
   Electronic data along with an isotope table and basic facts.
   http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/99.html

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

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

It's Elemental: Einsteinium
   Basic physical and historical information.
   http://education.jlab.org/itselemental/ele099.html

LANL: Einsteinium
   Basic information, history, and isotopes.
   http://periodic.lanl.gov/elements/99.html

Lenntech: Einsteinium
   Physical data and chemical properties.
   http://www.lenntech.com/Periodic-chart-elements/Es-en.htm

Visual Elements: Einsteinium
   Discovery, general and physical information, and ionisation energies.
   http://www.chemsoc.org/viselements/pages/einsteinium.html