Uddin, S. A., M. Rahman, M. Khan, M. M. Rahman, M. Islam, S. Ghose, M. Huda, S. Begum, P. Basak, and M. T. Rahman. “A Study of Echocardiographic Changes Among the Patients of COPD”. TAJ: Journal of Teachers Association, vol. 28, no. 1, Dec. 2018, pp. 16-20, doi:10.3329/taj.v28i1.39062.