Yang, S. H., S. J. Choi, C. R. Roh, et al. "Multiple courses of antenatal corticosteroid therapy in patients with preterm premature rupture of membranes" Journal of Perinatal Medicine, 32.1 (2005): 42-48. Retrieved 19 May. 2013, from doi:10.1515/JPM.2004.007

Yang, S., Choi, S., Roh, C., et al. (2005). Multiple courses of antenatal corticosteroid therapy in patients with preterm premature rupture of membranes. Journal of Perinatal Medicine, 32(1), pp. 4-102. Retrieved 19 May. 2013, from doi:10.1515/JPM.2004.007

Yang, S. H., S. J. Choi, C. R. Roh, et al. 2005. Multiple courses of antenatal corticosteroid therapy in patients with preterm premature rupture of membranes. Journal of Perinatal Medicine. 32(1): 4-102. Retrieved 19 May. 2013, from doi:10.1515/JPM.2004.007