1. The best collections of historical research into teratology and its etiology are: G. M. Gould and W. L. Pyle, Anomolics and Curiosities in Medicine (Philadelphia: W. B. Saunders, 1897).
2. Josef Warkany, Congenital Malformations (Chicago: Year Book Medical Publishers, 1971).
3. Josef Warkany, “Congenital Malformation in the Past,” Journal of Chronic Diseases 10 (1959), 84 ff.
4. J. W. Ballantyne, “The Teratological Records of Chaldea,” Teratologia 1 (1894), 12.
5. Cicero, De Senectute, de Amicita, de Divinatione, trans. W. A. Falconer (Cambridge: Harvard University Press, 1908).