1. H. L. Rook, private communication, 1972.
2. H. P. Yule, in J. R. DeVoe (Ed.), NBS Special Publication 312, Modern Trends in Activation Analysis, June, 1969, p. 1155.
3. H. P. Yule, in A. O. Brunfelt and E. Steinnes, Activation Analysis in Geochemistry and Cosmochemistry, Universitetsforlaget, Oslo, 1971, p. 145.
4. H. P. Yule, H. L. Rook, to be published.
5. H. P. Yule, in NBS Technical Note 548, P. D. LaFleur and D. A. Becher (Eds), 1970, p. 124.