Taher, M.A. et al. 2012. 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 Medical Journal. 2, 2 (Oct. 2012), 77–80. DOI:https://doi.org/10.3329/birdem.v2i2.12306.