1. C. R. Creger, M. M. A. Ansari, J. R. Couch, L. B. Colvin,Intern. J. Appl. Radiation Isotopes, 18 (1967) 71.
2. Packard Tri-Carb Liquid Scintillation Spectrometer Operation Manual, Packard Instrument Co., Downers Grove, Illinois.
3. W. H. Fuller, J. E. Hardcastle, USAEC Res. and Devel. Report, 1966. Contract No. At (11–1) 947.
4. J. E. Hardcastle, The Radioassay of45Ca and89Sr from Biological Systems by Liquid Scintillation Counting, Dissertation, University of Arizona, Tucson, 1967.
5. M. F. L'Annunziata, W. H. Fuller,Soil Sci., 105 (1968) 311.