1. Bourne, G., The Human Amnion and Chorion, 276 (Lloyd–Luke (Medical Books) Ltd., London, 1962).
2. Krantz, K. E., and Parker, J. C., Clin. Obstet. and Gynec., 6, 26 (1963).
3. Padykula, H. A., in Histology, second ed. (edit. by Greep, R. O.) (Blakiston Division, McGraw-Hill Book Company, New York, 1966).
4. Rhodin, J. A. G., and Terzakis, J., J. Ultrastructure Res., 6, 88 (1962).
5. Coujard, R., Lapage, F., and Schramm, B., Bull. Fed. Soc. Gynec. et d'Obstet., suppl. 4, 522 (1952).