ChemGlobe: Californium
- Electronic and thermal data along with an isotope table.
- http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/98.html

LANL: Californium
- Basic information and history.
- http://periodic.lanl.gov/elements/98.html

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

EnvironmentalChemistry.com: Californium
- Atomic structure, chemical and physical properties, and table of nuclides.
- http://environmentalchemistry.com/yogi/periodic/Cf.html

Visual Elements: Californium
- General and physical information, uses, and key isotopes.
- http://www.chemsoc.org/viselements/pages/californium.html

It's Elemental: Californium
- Basic physical and historical information.
- http://education.jlab.org/itselemental/ele098.html

ChemicalElements.com: Californium
- Basic information, atomic structure, and isotopes table.
- http://www.chemicalelements.com/elements/cf.html

Britannica Nobel Prizes: Californium
- Overview and basic data.
- http://www.britannica.com/nobel/micro/98_61.html