1. R.J. Stamets (Metal Finishing 73 No. 7 [1975] 29/33).
2. C. Agte, J. Vacek (Wolfram und Molybdän, Akademie-Verl., Berlin 1959, pp. 214/34).
3. W.J. Kroll (in: H. H. Uhlig, The Corrosion Handbook, Wiley, New York 1948, p. 330).
4. CA. Hampel (Ind. Eng. Chem. 53 [1961] 90/6).
5. M. G. Fontana (Ind. Eng. Chem. 44 No. 7 [1952] 71A/74A;