1. Unpublished.
2. Mary T. Wright and W. Adair Morrison: 1960 Literature Survey—Report no. 61-GP-219A; available from authors, General Electric Research Laboratory, P. O. Box 1088, Schenectady, N. Y.
3. W. Shockley: On the Statistics of Individual Variations of Productivity in Research Laboratories, Proc. of the Inst, of Radio Engineers, vol. 45, 1957, p. 279 and vol. 45, 1957, p. 1409.
4. J. C. Fisher: Basic Research in Industry, Science, vol. 129, 1959, p. 1653 and vol. 130, 1959, p. 1220.
5. J. H. Westbrook: “Identifying Significant Research”, Science, vol. 132, 1960, p. 1229 and vol. 133, 1961, p. 1138.