Ireneus Eibl-Eibesfeldt, Ethology: The Biology of Behavior, 2d ed. (Holt, Rinehart and Winston, New York, 1977).
68
Информация об улыбке слепых детей — см. Eibl-Eibesfeldt, Ethology.
69
Melvin J. Konner, Aspects of the Developmental Ethology of a Foraging People, in N. G. Blurton Jones, ed., Ethological Studies of Child Behaviour (Cambridge University Press, 1972), pp. 285—304; Joel Greenberg, The Brain and Emotions, Science News 112: 74-75 (1977).