Ulas Tugcu, A., D. Anuk Ince, O. Turan, and A. Ecevit. “Comparison of Two Surfactant Preparates Derived from the Same Animal for the Treatment of Respiratory Distress Syndrome”. Annals of Medical Research, vol. 26, no. 12, May 2021, pp. 2948-51, http://www.annalsmedres.org/index.php/aomr/article/view/1886.