| Americium: Data tables and historic information. |
| Britannica Nobel Prize: Americium: Overview and basic data. |
| ChemGlobe: Americium: Electronic, thermal, and steric data along with an isotope table. |
| ChemicalElements.com: Americium: Basic information, atomic structure, and isotopes. |
| EnvironmentalChemistry.com: Americium: Atomic structure, properties, and table of nuclides. |
| It's Elemental: Americium: Basic physical and historical information. |
| LANL: Americium: Basic information and history. |
| Lenntech: Americium: Physical data, chemical properties, health and environmental effects. |
| Visual Elements: Americium: Image, general and physical information, and key isotopes. |
| WebElements: Americium: Extensive information on history, uses, compounds, and properties. |