@article {Rietema, author = {H. Rietema and S. Holverda and H.J. Bogaard and J. Tim Marcus and H.J. Smit and N. Westerhof and P.E. Postmus and A. Boonstra and A. Vonk-Noordegraaf}, title = {Sildenafil treatment in COPD does not effect stroke volume or exercise capacity}, year = {2007}, doi = {10.1183/09031936.00114207}, publisher = {European Respiratory Society}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/early/2007/12/19/09031936.00114207}, eprint = {https://erj.ersjournals.com/content/early/2007/12/19/09031936.00114207.full.pdf}, journal = {European Respiratory Journal} }