1. G. Allard, “X-Ray Study of Some Borides,”Bull. Soc. Chim. Fr., 51, 1213–1215 (1932) in French. (Equi Diagram, Crys Struc- ture; Experimental)
2. M. von Stackelberg and F. Neumann, “Crystal Structure of Borides of Composition MeB6,”Z. Phys. Chem. B, 19, 314–320 (1932) in German. (Equi Diagram, Crys Structure; Experimental)
3. V.S. Neshpor and G.V. Samsonov, “New Borides of the Rare EarthMetals,”Zh. Fiz. Khim., 32,1328–1333 (1958) in Russian. (Equi Diagram, Crys Structure; Experimental)
4. H.A. Eick and P.W. Gilles, “Precise Lattice Parameters of Se- lected Rare Earth Tetra- and Hexa-Borides,”J. Am. Chem. Soc., 81, 5030–5032 (1959). (Equi Diagram, Crys Structure; Experimental)
5. N.N. Tvogorov, “Hexaborides of the Rare Earth Elements and Yttrium,”Zh. Neorg. Khim., 13, 1961–1966 (1959) in Russian; TR:Russ. J. Inorganic Chem., 4, 890–893 (1959). (Equi Diagram, Crys Structure; Experimental)