Langah, A., N. Ghaffar, N. A. Memon, H. Siyal, A. Nadeem, and J. Latif. “Factors Associated With Pneumothorax in Premature Neonates of Interior Sindh”. Pakistan Journal of Chest Medicine, vol. 28, no. 4, Dec. 2022, pp. 503-8, http://www.pjcm.net/index.php/pjcm/article/view/872.