1. Gairdner, D. M. T., in “Recent Advances in Paediatrics” (Churchill, London, 1954).
2. Potter, E. L., and Adair, F. L., “Fetal and Neo-natal Death”, 2nd edit. (Univ. Chicago Press, 1949).
3. Policard, A., and Müller, F., Bull. Histol. Tech. Micro., 21, 67 (1944).
4. Whitehead, W. H., Windle, W. F., and Becker, R. F., Anat. Rec., 83, 255 (1942).
5. Potter, E. L., and Bohlender, G. P., Amer. J. Obst. Gynec., 42, 14 (1941).