1. McNay MB, Fleming JE: Forty years of obstetric ultrasound 1957–1997: from A-scope to three dimensions. Ultrasound Med Bio 1999, 25(1):3–56.
2. Alan B, Goya C, Tunc S, Teke M, Hattapoglu S. Assessment of placental stiffness using acoustic radiation force impulse Elastography in pregnant women with fetal anomalies. Korean J Radiol. 2016;17(2):218–23.
3. Padula F, Laganà A, Vitale S, Mangiafico L, D’Emidio L, Cignini P, Giorlandino M, Gulino F, Capriglione S, Giorlandino C. Ultrasonographic evaluation of placental cord insertion at different gestational ages in low-risk singleton pregnancies: a predictive algorithm. Facts Views Vis ObGyn. 2016;8(1):3.
4. Andrietti S, Carlucci S, Wright A, Wright D, Nicolaides KH. Repeat measurements of uterine artery pulsatility index, mean arterial pressure and serum placental growth factor at 12, 22 and 32 weeks in prediction of pre-eclampsia. Ultrasound Obstet Gynecol. 2017;50(2):221–7.
5. WHO. WHO manual of diagnostic ultrasound, vol. 2. 2nd ed. Geneva: Switzerland World Health Organization: World Health Organization & World Federation for Ultrasound in Medicine and Biology; 2013.