EnvironmentalChemistry.com: Praseodymium EnvironmentalChemistry.com: Praseodymium: Atomic structure, chemical and physical properties, and table of nuclides. (Praseodymium) http://environmentalchemistry.com/yogi/periodic/Pr.html
Praseodymium Praseodymium: Data tables and historic information. (Praseodymium) http://www.scescape.net/~woods/elements/praseodymium.html
WebElements: Praseodymium WebElements: Praseodymium: Extensive information on history, uses, occurrence, compounds, and properties. (Praseodymium) http://www.webelements.com/webelements/elements/text/Pr/key.html
ChemGlobe: Praseodymium ChemGlobe: Praseodymium: Electronic, thermal, and steric data along with an isotope table. (Praseodymium) http://www.vcs.ethz.ch/chemglobe/ptoe/_/59.html
Lenntech: Praseodymium Lenntech: Praseodymium: Physical data, chemical properties, health and environmental effects. (Praseodymium) http://www.lenntech.com/Periodic-chart-elements/Pr-en.htm