Britannica Nobel Prize: Krypton
   Overview and basic data.
   http://www.britannica.com/nobel/micro/329_89.html

ChemGlobe: Krypton
   Electronic, thermal, and steric data along with an isotope table.
   http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/36.html

Chemical Elements.com: Krypton
   Basic information, atomic structure, and table of isotopes.
   http://www.chemicalelements.com/elements/kr.html

EnvironmentalChemistry.com: Krypton
   Atomic structure, properties, and table of nuclides.
   http://environmentalchemistry.com/yogi/periodic/Kr.html

Especiál Gas Inc.: Krypton
   Numeric data, uses, and general information.
   http://www.c-f-c.com/specgas_products/krypton.htm

It's Elemental: Krypton
   Basic physical and historical information.
   http://education.jlab.org/itselemental/ele036.html

LANL: Krypton
   History, sources, isotopes, and uses.
   http://periodic.lanl.gov/elements/36.html

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

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

What Does the Element Krypton Look Like?
   Explanation with photographs.
   http://education.jlab.org/qa/krypton.html

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