Ali, Azmat, et al. “COMPARISON OF PERINATAL OUTCOME OF GROWTH RESTRICTED FOETUSES WITH NORMAL AND ABNORMAL UMBILICAL ARTERY DOPPLER WAVEFORMS”. Journal of Ayub Medical College Abbottabad, vol. 26, no. 3, Sept. 2014, pp. 344-8, https://www.jamc.ayubmed.edu.pk/index.php/jamc/article/view/1503.