Dose–response characteristics during long–term inhalation of nitric oxide in patients with severe acute respiratory distress syndrome: a prospective, randomized, controlled study. - Gerlach,H.; Keh,D.; Semmerow,A.; Busch,T.; Lewandowski,K.; Pappert,DM.; Rossaint,R.; Falke,KJ.. (Am J Respir Crit Care Med, 2003)