CHAKARVARTY, N.; SRIVASTAV, K.; KHANDURI, S. A study to evaluate a correlation between various Gray Scale parameters and period of gestation. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, [S. l.], v. 7, n. 6, p. 2434–2440, 2018. DOI: 10.18203/2320-1770.ijrcog20182364. Disponível em: https://www.ijrcog.org/index.php/ijrcog/article/view/4844. Acesso em: 14 oct. 2025.