L. Songsathaporn, L. Puttanavijarn, and D. Sudjai, “Normative Values of Uterine Artery Doppler Pulsatility Index using Transvaginal Ultrasound in Women between 18-24+6 Weeks of Gestation at Rajavithi Hospital”, Thai J Obstet Gynaecol, vol. 29, no. 4, pp. 227–235, Jul. 2021.