Technetium

ChemicalElements.com: Technetium - Basic information, atomic structure, and isotopes.
http://www.chemicalelements.com/elements/tc.html

Visual Elements: Technetium - Image, general and physical information, source, uses, key isotopes, and ionisation energies.
http://www.chemsoc.org/viselements/pages/technetium.html

ChemGlobe: Technetium - Electronic, thermal, and steric data along with an isotope table.
http://partisans.spurious.biz/~pkremer/projects/chemglobe/ptoe/_/43.html

Wikipedia: Technetium - Properties of the element, including its history, applications, and characteristics.
http://en.wikipedia.org/wiki/Technetium

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

WebElements: Technetium - Extensive information on history, uses, occurrence, compounds, and properties.
http://www.webelements.com/webelements/elements/text/Tc/key.html

It's Elemental: Technetium - Basic physical and historical information.
http://education.jlab.org/itselemental/ele043.html

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

Radiochemistry of Technetium - Full text of the monograph by Edward Anders (Enrico Fermi Institute and Dept. of Chemistry, University of Chicago, Chicago, Illinois). [PDF] <small>(November, 1960)</small>
http://library.lanl.gov/cgi-bin/getfile?rc000035.pdf

LANL: Technetium - History, isotopes, properties, and handling.
http://periodic.lanl.gov/elements/43.html