Waseem, N., I. ., A. Khan, A. Malik, and R. A. Khan. “FREQUENCY OF EARLY ATRIAL FIBRILLATION IN POST MITRAL VALVE REPLACEMENT SURGERY”. Journal of Postgraduate Medical Institute, vol. 30, no. 2, Apr. 2016, https://www.jpmi.org.pk/index.php/jpmi/article/view/1894.