1. D. K. Belyaev, ?Genetic aspects of the domestication of animals,? in: Problems of the Domestication of Animals and Plants [in Russian], Nauka, Moscow (1972), p. 39.
2. E. M. Nikulina, Some Neurohumoral Mechanisms of the Aggressive Behavior of rats: Author's Abstract of Dissertation for the Degree of Candidate of Biological Sciences [in Russian], Moscow State University, Moscow (1977).
3. N. K. Popova, N. N. Voitenko, and L. N. Trut, ?Change in the content of serotonin and 5-hydroxyindoleacetic acid during the selection of silver foxes according to behavior,? Dokl. Akad. Nauk SSSR,223, No. 6, 1496 (1975).
4. N. K. Popova, E. V. Naumenko, and V. G. Kolpakov, Serotonin and Behavior [in Russian], Nauka, Novosibirsk (1978).
5. V. Yu. Urbakh, Mathematical Statistics for Biologists and Physicians [in Russian], Nauka, Moscow (1963).