Hassan, Khalid S, Maha M. El Tantawi, Adel S. AlAgl, Amani M Alnimr, and Yasmeen A Haseeb. 2016. “Sensitivity and Specificity of Subgingival Bacteria in Predicting Preterm Birth- a Pilot Cohort Study”. International Journal of Health Sciences 10 (4). https://ijhs.qu.edu.sa/index.php/journal/article/view/1366.