1. E.I. Hamilton, Elemental Analysis of Biological Material, Techn. Rept. Ser. No. 197, IAEA /1980/ pp. 40–59.
2. P.R. Ehrlich, A.H. Ehrlich, J.P. Holdren, Ecoscience Population, Resources, Environment, W.H. Freeman and Co., San Francisco, 1979, 556–574.
3. K. Beijer, A. Jernelöv, Handbook of Toxicology, Holland Bio-Med. Press, 1979.
4. IAEA, Analytical Quality Control Service Programme, LAB/243, 1987–1988, IAEA.
5. A.P. Grimanis, N. Kalogeropoulos, M. Vassilaki-Grimani, M. Angelidis, D. Zafiropoulos,J. Radioanal. Nucl. Chem., Articles; 114 /1987/ 45.