Saim Sağ, et al. “Treatment With a Combination of Bosentan and Sildenafil Allows for Successful Liver Transplantation in a Patient With Portopulmonary Hypertension”. Turkish Journal of Gastroenterology, vol. 25, no. 4, July 2019, pp. 429-32, https://tjg.avesjournals.com/index.php/tjg/article/view/2990.