“Doppler Flow Velocity Indices (RI, PI, S/D & PSV) of Fetal Middle Cerebral Artery in Normal Pregnancies: Correlation with Gestational Age of 20 to 40 Weeks”, Birdem Med J, vol. 2, no. 2, pp. 77–80, Oct. 2012, doi: 10.3329/birdem.v2i2.12306.