1. Altman, Ph. L., Dittmer, D. S.: Biol. Data Book, 2. Ed., Vol. II. Bethesda 1972
2. Clerici, E., Ciccarone, P.: Nature (Lond.)207, 762–763 (1965)
3. Hajdu, S. I., Foraker, A. G.: Arch. Path.77, 450–456 (1964)
4. Haller, C. v., Lade, R.: Anat. Anz.135, 102–115 (1974)
5. Haller, C. v.: Z. exp. Chir.6, 324–336 (1973)