Amirthalingam, M., P. Dakshnamurthy, and V. Shanmugham. “A Study of Birth Defects in a Tertiary Care Teaching Hospital at Chennai, India”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 6, no. 7, June 2017, pp. 3067-70, doi:10.18203/2320-1770.ijrcog20172936.