Hafizullah, M., Z. Bachaa, M. ul Hassan, A. Rehman, and M. A. Taqweem. “Aortic Stenosis - How Severe Is Severe?”. Journal of Postgraduate Medical Institute, vol. 16, no. 1, Sept. 2011, https://www.jpmi.org.pk/index.php/jpmi/article/view/752.