Kawilarang, Stella, I Ketut Suwiyoga, and Tjokorda GA Suwardewa. 2019. “Elevated Serum Ferritin and Interleukin-6 Level As the Risk Factor in Preterm Labor: Kadar Feritin Dan Interleukin-6 Serum Yang Tinggi Merupakan Faktor Risiko Terjadinya Persalinan Preterm”. Indonesian Journal of Obstetrics and Gynecology 7 (2):101-4. https://doi.org/10.32771/inajog.v7i2.1002.