Madas S, Vittal DS. Estimation of measured pulmonary artery to aorta ratio for prognosis of pulmonary hypertension in chronic obstructive pulmonary disease patients. Int J Adv Med [Internet]. 2017 Jan. 2 [cited 2025 Dec. 25];3(2):200-5. Available from: https://www.ijmedicine.com/index.php/ijam/article/view/164