Inhaled nitric oxide in preterm infants: an individual-patient data meta-analysis of randomized trials. - Askie, L; Ballard, R; Cutter, G; Dani, C; Elbourne, D; Field, D; Hascoet, J; Hibbs, A; Kinsella, J; Mercier, J; Rich, W; Schreiber, MD; et al. (Pediatrics, 2011)