TAWFIK, W. M. Evaluation of yolk sac size and embryonic heart rate in first trimester and pregnancy outcome. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, [S. l.], v. 10, n. 8, p. 2975–2980, 2021. DOI: 10.18203/2320-1770.ijrcog20212943. Disponível em: https://www.ijrcog.org/index.php/ijrcog/article/view/10484. Acesso em: 20 apr. 2025.