N. Goyal, S. Singh, A. Mathur, N. Gupta, D. K. Makkar, and V. P. Aggarwal, “Perceived stress among gravid and its effect on their oral health in Sri Ganganagar, Rajasthan, India”, Int J Reprod Contracept Obstet Gynecol, vol. 6, no. 4, pp. 1381–1387, Mar. 2017.