1. R. M. German, D. C. Wright andR. F. Gallant, in Proceedings of 5th International Conference on Precious Metals, Toronto, June 1980, edited by R. O. McGachie and A. D. Bradley (Pergamon Press, Canada, 1981) p. 253.
2. D. F. Taylor, V. H. Baldwin andK. F. Leinfelder,J. Dent. Res. 61 (1982) 344.
3. N. K. Sarkar, W. Guillory andJ. Sturdevant,ibid. 61 (1982) 246.
4. E. Raub andG. Wörwag,Z. Metallkde 46 (1955) 119.
5. M. Ohta, T. Shiraishi andM. Yamane,J. Mater. Sci. 21 (1986) 529.