1. Ames Laboratory, 2013. What are the Rare Earths? Ames, Iowa. Retrieved on August 14, 2013 from www.ameslab.gov/dmse/rem/what-are-rare-earths.
2. The demand for rare earth materials in permanent magnets;Constantinides,2012
3. Okamoto, H., 2006. Fe-Nd Phase Diagram, ASM Alloy Phase Diagrams Center, P. Villars, editor-in-chief: H. Okamoto and K. Cenzual, section editors: http://www1.asminternational.org/AsmEnterprise/APD, ASM International, Materials Park, OH, USA.
4. High Purity Rare Earth Metals Preparation;Riedemann,2011
5. Rare earth elements in transportation;Constantinides,2013