1. Johnston, M.C.: Regional embryology, some aspects relevant to the pathogenesis of craniofacial malformations, in Converse, J.M., and Pruzansky, S., editors: Proceedings, International Conference on Craniofacial Malformations, St. Louis, The C. V. Mosby Company. In press.
2. Manual of antenatal pathology and hygiene: The embryo;Ballantyne,1904
3. Fetal malformations caused by amnion rupture during gestation;Torpin,1968
4. Ebbin, A.: Personal communication.