Hafnium

Minor Metal Trade Association
Benefits and promotes the interests of its international membership, comprising companies actively involved in all aspects of the international trade of minor metals in all their various forms.
Wikipedia
Definition from open source encyclopedia.
Phoenix College & Maricopa Community College District
Chemical and Isotopic information.
Lenntech
Information and history.
United States Geological Survey
Hafnium Statistics and Information
Mineral Information Institute
Not-for-profit organization dedicated to educating youth about the science of minerals and other natural resources, and about their importance in our every day lives.
Occupational Safety and Health Administration
Health and safety information for those handling Hafnium.
Radiochemistry Society
Radiochemistry of Hafnium.
Britannica.com
Discovery of Hafnium.
Webelements
Basic Hafnium Information
Gamma-ray weapons could trigger next arms race
New Scientist - 13 August 2003