Comparison of efficacy and safety of two available natural surfactants in Iran, Curosurf and Survanta in treatment of neonatal respiratory distress syndrome: a randomized clinical trial - Najafian, B; Karimi-Sari, H; Khosravi, M H; Nikjoo, N; Amin, S; Shohrati, M (Contemp Clin Trials Commun, 2016)