1. E. B. Norris, S. A. Viaclovsky, andA. R. Whiting Proceedings of the Seventh Symposium on Non-destructive Evaluation of Components and Materials in Aerospace, Weapon Systems and Nuclear Applications (American Society for Non-Destructive Testing, San Antonio, Texas, April 1969), p. 32.
2. E. H. Andrews andJ. Willis, to be published.
3. E. H. Andrews andL. Bevan, to be published.