1. 1) United Nations Scientific Committee on the Effects of Atomic Radiation : "Sources and Effects of Ionizing Radiation, UNSCEAR 2000 report to the General Assembly with Annexes, Volume I", p. 115, (2000), (New York).
2. 4) C. W. Sill, K. W. Puphal, F. D. Hindman : Anal. Chem., 46, 1725, (1974).
3. 5) E. K. Hyde : "The Radiochemisry of Thorium", NAS-NS 3004, (1960), (U.S. AEC).
4. 7) HASL EML-300 procedure manual : "Th-01-RC", Section 4.5.4, Vol. II, 28th Edition, Environmental Measurement Laboratory, (1997), (Department of Energy, United State).
5. 8) E. P. Horwitz, M. L. Dietz, R. Chiarizia, H. Diamond, S. L. Maxwell III, M. R. Nelson : Anal. Chim. Acta, 310, 63 (1995).