Muhammad Aamir khan, Dawood Kamal Mehsud, Tahseen Ahmed, and Muhammad Waseem. 2017. “AORTIC ROOT REPLACEMENT: CLASSICAL BENTALL VERSUS COPELAND’S MODIFICATION”. Pakistan Armed Forces Medical Journal 67 (SUPPL-2):S242-47. https://pafmj.org/PAFMJ/article/view/11921.