YADAV, R.; SINGH, U. Study of changes in levels of salivary estriol and progesterone in preterm labor in comparison to normal pregnancy. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, [S. l.], v. 8, n. 12, p. 4660–4667, 2019. DOI: 10.18203/2320-1770.ijrcog20195223. Disponível em: https://www.ijrcog.org/index.php/ijrcog/article/view/7556. Acesso em: 13 oct. 2025.