1) L. BOGDANDY and R. WARTMAN: Arch. Eisenhuttenw., 35 (1965), p.221
2) V. KOUMP, R. H. TIEN, R.G. OLSSON, and T. F. PERZAH: Process Simulation and Control in Iron and Steelmaking, ed. by J. M. Uys and H. L. Bishop, (1966), p.125 [Gordon and Breach Science Pub.]