Oral sildenafil as long-term adjunct therapy to inhaled iloprost in severe pulmonary arterial hypertensionHossein Ardeschir Ghofrani, Friedrich Grimminger, Norbert Weißmann et al.|Journal of the American College of Cardiology|2003Cited by 368
Sildenafil for Long-Term Treatment of Nonoperable Chronic Thromboembolic Pulmonary HypertensionHossein Ardeschir Ghofrani, Friedrich Grimminger, Ralph T. Schermuly et al.|American Journal of Respiratory and Critical Care Medicine|2003Cited by 286
Sildenafil treatment for portopulmonary hypertensionFrank Reichenberger, Hossein Ardeschir Ghofrani, Werner Seeger et al.|European Respiratory Journal|2006Cited by 215