1. Fathi Habashi, editor, Handbook of Extractive Metallurgy, Volume III (Weinheim, Germany: Wiley VCH, 1997).
2. Erik Lassner and Wolf-Dieter Schubert, Tungsten—Properties, Chemistry, Technology of the Element, Alloys, and Chemical Compounds (New York: Kluwer Academic/Plenum Publishers, 1999).
3. Mathias Bohnet, editor, Ullmann’s Encyclopedia of Industrial Chemistry, 6th edition, Volume 37 (Weinheim, Germany: Wiley VCH, 2003).
4. Mathias Bohnet, editor, Ullmann’s Encyclopedia of Industrial Chemistry, 6th edition, Volume 22 (Weinheim, Germany: Wiley VCH, 2003).
5. Werner V. Schulmeyer and Hugo M. Ortner, “Mechanisms of the Hydrogen Reduction of Molybdenum Oxides,” International Journal of Refractory Metals & Hard Materials, 20 (2002), pp. 261–269.