1. G.B. Haxel, J.B. Hedrick, G.J. Orris, Rare Earth Elements—Critical Resources for High Technology.
2. B. Plumer, China's grip on the world's rare earth market may be slipping, Washington Post, 2012.
3. The rare-earth crisis;Bourzac;Technol. Rev.,2011
4. Advances in magnetics hard magnetic materials: a perspective;Coey;IEEE Trans. Magn.,2011
5. Permanent magnets: plugging the gap;Coey;Scr. Mater.,2012