1. Bulletin;GR Fitterer,1945
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3. G. R. Fitterer: Some Observations of Slag-Metal Relations in the Acid Open Hearth Steel Furnace, Journal of Metals, Dec., 1953, pp. 1634–1640.
4. J. W. Linhart: A Control Procedure for the Refining of Acid Open Hearth Heats, Open Hearth Proceedings, 1963, p. 137.