1. E. Heyn and O. Bauer, J. Iron Steel Inst. 79 (1909) 109.
2. C. Hambuechen, Bulletin, University of Wisconsin, Engineering Series, No. 8 (1900). Cited in W. D. France Jr, Corrosion-NACE 26 (1970) 189.
3. T. Andrews, Proc. Inst. Civil Eng. (British) 118 (1894) 356.
4. W. H. Walker and C. Dill, Proc. Amer. Soc. Test. Mater. 7 (1907) 230.
5. R. Franks, in ?The Corrosion Handbook?, edited by H. H. Uhlig (J. Wiley and Sons, New York, 1948) p. 150.