1. Harries, D. R., J. Iron and Steel Inst., 194, 289 (1960).
2. Fennell, J., and Roberts, A. C. (unpublished results).
3. Hughes, N. A., and Caley, J., J. Nucl. Materials, 10, 60 (1963).
4. Robertshaw, F. C., Moteff, J., Kingsbury, F. D., and Pugacz, M. A., A.S.T.M. Spec. Tech. Pub., No. 341, 372 (1963).
5. Hinkle, N. E., A.S.T.M. Spec. Tech. Pub., No. 341, 344 (1963).