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2. Arshavskiy, I. A. (1960): See Tu?ek, 1965.
3. Assali, N. S.: Biology of gestation, Vol. II: The foetus and neonate. New York: Academic Press 1968.
4. Caldeyro-Barcia, R., Méndez-Bauer, C., Poseiro, J. J., Escarcena, L. A., Posé, S. V., Bienarz, J., Arnt, I., Gulin, L., Althabe, O.: Control of human fetal heart during labor. In: The heart and circulation in the newborn and infant. D. E. Cassels (ed.). New York: Grune and Stratton Inc. 1966.
5. Cohn, A. E., Lewis, T.: J. exp. Med.18, 739?747 (1913).