Yeral, I., Y. Simsek, D. Seckin, and N. Danisman. “Spontaneous Heterotopic Pregnancy With Term Delivery of a Live Infant”. Annals of Medical Research, vol. 18, no. 1, May 2021, pp. 0054-6, http://www.annalsmedres.org/index.php/aomr/article/view/3313.