Wibowo, Noroyono, and Fitriana fitriana. 2019. “The Levels of Zinc, Selenium, Iron and Copper in Preterm Pregnancy Do Not Differ With Those of Healthy Pregnancy: Kadar Seng, Selenium, Besi Dan Tembaga Pada Kehamilan Prematur Tidak Berbeda Dengan Kehamilan Sehat”. Indonesian Journal of Obstetrics and Gynecology 7 (2):86-91. https://doi.org/10.32771/inajog.v7i2.880.