1. Benijts-Claus, C. and Persoone, G.: 1975, Med. Fac. Landbouww. Rijksuniv. Gent. 30, 1161.
2. Bliss, C. I.: 1952, Statistics of Bioassay, Academic Press, N.Y., pp. 445?628.
3. Brooker, M. P. and Edward, R. W.: 1973, Freshwater Biol. 3, 157.
4. Dubois, M., Gilles, K. A., Hamilton, J. K., Repers, P. A., and Smith, F.: 1956, Analyt. Chem. 18, 350.
5. Finney, D. J.: 1964a, Statistical Method in Biological Assay, Hafner N.Y., 668 pp.