Wibowo, N.; fitriana, F. 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. Indones J Obstet Gynecol 2019, 7, 86-91.