1. The reduction of rare earth oxides to metal and their subsequent rolling;Pengo;Nucl. Instrum. Methods Phys. Res., Sect. A,1991
2. Preparation of yttrium fluoride using fluorine;Tischer;U.S. At. Energy Comm. IS-8,1959
3. Preparative Methods in Solid State Chemistry;Bougon,1972
4. Fluorination of metals and metal oxides by gas solid reaction;Kwon;J. Ind. Eng. Chem.,2002
5. Extractive Metallurgy of Rare Earths;Gupta,2004