1. Bennett, I. L. (1950). Bull. Jokns Hopk.Hosp., £7, 290.
2. Mollendorff's Handbuch der mikroscopischen Anatomie des;Be-nninghoff, A.;Menschen,1930
3. Springer, Berlin. Cited by Franklin, K. J. (1948).
4. Cardicvasrular Stidies;Franklin, K.J.,1948
5. Uatzi, W. (1929). Arch. Anat. (Strasbourg), 10, 371.