Marpaung, J. 2016. Association between the thickness of the collagen in the amniotic membrane with the incidence of premature rupture of membranes. International Journal of Reproduction, Contraception, Obstetrics and Gynecology. 5, 2 (Dec. 2016), 296–299. DOI:https://doi.org/10.18203/2320-1770.ijrcog20160359.