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.
• WebElements: Holmium - Extensive information on history, uses, occurrence, compounds, and properties.
• Wikipedia: Holmium - Properties of the element, including its history, applications, and characteristics.