1. William T. Lanford, Jr., et al., ed., The Making, Shaping and Treating of Steel, 10th edition, (Pittsburgh, Herbick & Held, 1985).
2. John T. Kopfle. “The History of Direct Reduction,” Direct Reduced Iron: Technology and Economics of Production and Use, ed. J. Feinman and D. R. MacRae, (Warrendale, PA: ISS-AIME, 1999).
3. Wade N. Harris. Midland-Ross Corporation: A Story of Diversification, (Newcomen Society in North America, 1964).
4. John T. Kopfle. A Better Mousetrap: The History of Midrex Technologies. Direct from Midrex, 1st Quarter, 2004, pp 3, 2nd Quarter, 2004, pp 6, 3rd Quarter, 2004, pp 11, and 4th Quarter, 2004, pp 6, Midrex Technologies,
http://www.midrex.com/
.
5. Donald Beggs and John C. Scarlett. Method of and Apparatus for Reducing Iron Oxide to Metallic Iron. US Patent 3748120, granted July 24, 1973.