Pengaruh pemberian beta-karoten, vitamin D3 dan seng menyertai terapi steroid antenatal terhadap kejadian penyakit membran hialin dan gangguan toleransi minum pada bayi prematur = The effect of administration of beta carotene, vitamin d3 and zinc accompanying antenatal steroid on hyaline membrane disease and feeding intolerance in premature neonates / Yuyun Lisnawati