1. D. Baird, J. Walker, and E. Holland (1955 ): in): British Obstetric and Gynaecological Practice. Vol. 2, Obstetrics . Heineraann, London, p. 851 .
2. J. Barcroft (1946 ): Researches on Prenatal Life . Vol. 1 . Blackwcl J, Oxford, p. 190 .
3. Prolapse of the umbilical cord
4. Prolapse of the umbilical cord
5. PRESENTATION AND PROLAPSE OF UMBILICAL CORD. An Analysis of 350 Cases