1. Altland, P.D.: Physiol. Zool. 22, 235 (1949) quoted after [18].
2. Altland, P.D.: J. Exp. Zool. 110, 1 (1949) quoted after [18].
3. Aste-Salazar, H., and A. Hurtado: The Affinity of Hemoglobin for O2 at Sea Level and at High Altitudes. Amer. J. Physiol. 142, 733 (1944).
4. Barcroft, J.: Researches on Pre-natal Life. Oxford: Blackwell Scientific Publications. 1946.
5. Babtels, H.: Chemical Factors Affecting Oxygen Carriage and Transfer from Maternal to Foetal Blood. In: J. Walker and A. C. Turnbull, Oxygen Supply to the Human Foetus, p. 29. Oxford: Blackwell Scientific Publications. 1959.