1. O.P. Naumkin, V.T. Terekhova and E.M. Savitskii,Izv. Akad. Nauk SSSR Met., No. 4, p 176–182 (1965); translated inRuss. Met., No. 4, p 128–136 (1965). Also see E.M. Savitskii, V.F. Terekhova, I.V. Burov and O.P. Naumkin, inRare Earth Research III, Proc. Fourth Conf. (1964), L. Eyring, Ed., Gordon and Breach, Science Publishers, Inc., NY, p 301–319 (1965).
2. P.I. Kripyakevich and I.I. Zalutskii, in E.M. Savitskii and V.F. Terekhova, Eds.,Voprosy Teorii i Primeniniya Redkozemelynkh Metallov., Akad. Nauk SSSR, Moscow, p 144–145 (1964); translated as U.S. Dept. Commerce JPRS-28849, p 188–190 (1964).
3. V.N. Rechkin, L.K. Lamikhov and T.L. Samsonova,Kristallografiya, 9, p 405–408 (1964); translated inSov. Phys.—Crystallogr., 9, p 325–327 (1964).
4. A.E. Dwight, U.S. At. Energy Comm., ANL-6330, p 156–158 (1960).
5. O. Schob and E. Parthé,Acta Cryst., 19, p 214–224 (1965).