1. K.A. Gschneidner, Jr., The Rare Earth Crisis—The Supply/Demand Situation for 2010-2015, Mater. Matters, 2011, 6, p 32–37
2. C.K. Gupta and N. Krishnamurthy, Extractive Metallurgy of Rare Earths, CRC Press LLC, Boca Raton, FL, 2004
3. CMI. Critical Materials Institute—Grand Challenge Problems
4. U.S. Geological Survey. Mineral Commodities Summary 2011. 2011. https://doi.org/10.1029/92gl00258
5. G.B. Haxel, J.B. Hedrick, and G. Orris, Rare Earth Elements—Critical Resources for High Technology, United States Geological Survey, Reston, VA, 2002