Thulium
Links
Visual Elements: Thulium
http://www.chemsoc.org/viselements/pages/thulium.html
Image, uses, physical information, and ionisation energies.
It's Elemental: Thulium
http://education.jlab.org/itselemental/ele069.html
Basic physical and historical information.
ChemicalElements.com: Thulium
http://www.chemicalelements.com/elements/tm.html
Basic information, atomic structure, and isotopes.
EnvironmentalChemistry.com: Thulium
http://environmentalchemistry.com/yogi/periodic/Tm.html
Atomic structure, chemical and physical properties, and table of nuclides.
WebElements: Thulium
http://www.webelements.com/webelements/elements/text/Tm/key.html
Extensive information on history, uses, occurrence, compounds, and properties.
Lenntech: Thulium
http://www.lenntech.com/Periodic-chart-elements/Tm-en.htm
Physical data, chemical properties, health and environmental effects.