7 links
ChemicalElements.com: Gadolinium
chemicalelements.com
Basic information, atomic structure, and isotopes.
Corrosionsource.com: Gadolinium
corrosionsource.com
History, occurrence, properties, isotopes, and uses.
EnvironmentalChemistry.com: Gadolinium
environmentalchemistry.com
Atomic structure, chemical and physical properties, and table of nuclides.
Lenntech: Gadolinium
lenntech.com
Physical data, chemical properties, health and environmental effects.
WebElements: Gadolinium
ebelements.com
Extensive information on history, uses, occurrence, compounds, and properties.
Wikipedia: Gadolinium
en.wikipedia.org
Properties of the element, including its history, applications, and characteristics.