See also:

• Science: Chemistry: Elements: Lanthanides  (2)

ChemGlobe: Holmium: - Electronic, thermal, and steric data along with an isotope table.

ChemicalElements.com: Holmium: - Basic information, atomic structure, and isotopes table.

EnvironmentalChemistry.com: Holmium: - Atomic structure, chemical and physical properties, and table of nuclides.

It's Elemental: Holmium: - Basic physical and historical information.

LANL: Holmium: - Basic information, history, and properties.

Lenntech: Holmium: - Physical data, chemical properties, health and environmental effects.

Visual Elements: Holmium: - Image, source, uses, key isotopes, and ionisation energies.

Wikipedia: Holmium: - Properties of the element, including its history, applications, and characteristics.