Sharma, J. B., D. Karmakar, S. Aggarwal, S. Singhal, K. K. Roy, and S. Kumar. “Prevalence of Gastro-Intestinal Symptoms During Pregnancy: A Questionnaire Based Study in a Tertiary Care Center of South Asia”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 3, no. 1, Dec. 2016, pp. 87-91, https://www.ijrcog.org/index.php/ijrcog/article/view/753.