Zareen, Nusrat, et al. “AN EARLY DIAGNOSIS OF FOETAL DISTRESS BY ESTIMATING THE MATERNAL BLOOD GAS LEVELS DURING INTRAPARTUM PERIOD”. Pakistan Journal of Physiology, vol. 4, no. 1, June 2009, pp. 13-16, https://pjp.pps.org.pk/index.php/PJP/article/view/641.