JEARRANAIKARN, W.; SIWADUNE, T. A Comparison of Cervical Ruler and Transvaginal Ultrasound for Cervical Length Measurement during Pregnancy. Thai Journal of Obstetrics and Gynaecology, Bangkok, Thailand, v. 29, n. 2, p. 65–72, 2021. DOI: 10.14456/tjog.2021.9. Disponível em: https://he02.tci-thaijo.org/index.php/tjog/article/view/218988. Acesso em: 1 oct. 2026.