Argon: Data tables and historic information.
Britannica Nobel Prize: Argon: Overview and basic data.
ChemGlobe: Argon: Electronic, thermal, and steric data along with basic information.
ChemicalElements.com: Argon: Basic information, atomic structure, and table of isotopes.
EnvironmentalChemistry.com: Argon: Atomic structure, chemical and physical properties, and table of nuclides.
Especiál Gas Inc.: Argon: Numeric data, uses, and general information.
It's Elemental: Argon: Basic physical and historical information.
LANL: Argon: Sources, properties, isotopes, and uses.
Lenntech: Argon: Physical data, chemical properties, health and environmental effects.
Visual Elements: Argon: General and physical information, uses, key isotopes, and ionisation energies.
WebElements: Argon: Extensive information on history, uses, occurrence, and properties of the element.
Wikipedia: Argon: Details the properties of the element, including its history, applications, and characteristics.