Gupta, Pooja, et al. “Evaluation of Uterine Biophysical Profile and to Assess Its Role in Predicting Conception Among Unexplained Primary Infertility Patients”. Indian Journal of Community Health, vol. 26, no. 4, Dec. 2014, pp. 401-5, https://www.iapsmupuk.org/journal/index.php/IJCH/article/view/447.