1. G. Allard, X-Ray Study of Some Borides, Bull. Soc. Chim. Fr., Vol 51, 1932, p 1213–1215 (in French). (Crys Structure; Experimental)
2. M. von Stackelberg and F. Neumann, The Crystal Structure of Borides with Composition MeB6, Z. Phys. Chem. B, Vol 19, 1932, p 314–320 (in German). (CrysStructure; Experimental)
3. P. Blum and F. Bertaut, Borides with Higher Content of Boron, Acta Crystallogr., Vol 7, 1954, p 81–86 (in French). (Crys Structure; Experimental)
4. B. Post, D. Moskowitz, and F.W. Glaser, Borides of Rare Earth Metals, J. Am. Chem. Soc., Vol 78, 1956, p 1800–1802. (Crys Structure; Experimental)
5. G.V. Samsonov and A.E. Grodshtein, Some of the Properties of the Hexaborides of the Alkaline Earth and of the Rare-Earth Metals, Zh. Fiz. Khim., Vol 30, 1961, p 379–381 (in Russian). (Crys Structure; Experimental)