1. A.E. van Arkel and J.H. de Boer, “Preparation of Pure Titanium, Zirconium, Hafnium, and Thorium Metal,”Z. Anorg. Allg. Chem., 148, 345–350 (1925) in German. (Equi Diagram; Experimental)
2. K. Moers, “Methods for the Preparation of Pure High-Melting Carbides, Nitrides, and Borides and a Description of a Few of Their Properties. II. The Preparation of Pure Carbides, Nitrides, and Borides by the Method of Growth and a Description of a Few of Their Properties,”Z. Anorg. Allg. Chem., 198, 243–261 (1931) in German. (Equi Diagram; Experimental)
3. O. Ruff, Congr. Chim. Ind., 15th Congr., Bruxelles, 68 (1935); quoted in [Hansen]. (Equi Diagram; Experimental)
4. F.W. Glaser, D. Moskowitz, and B. Post, “A Study of Some Binary Hafnium Compounds,”Trans. AIME, 197(9), 1119–1120, (1953). (Crys Structure; Experimental)
5. G.L. Humphrey, “Heats of Formation of Hafnium Oxide and Hafnium Nitride,”J. Am. Chem. Soc., 75, 2806–2807 (1953). (Thermo; Experimental)