"Prevalence of Vitamin D Deficiency and Insufficiency Across Trimesters of Pregnancy in Maiduguri, Nigeria: A Cross-Sectional Study" (2021) African Journal of Biomedical Research, 24(1), ص 53–57. موجود في: https://www.ojshostng.com/index.php/ajbr/article/view/1689 (تاريخ الوصول: 21 مايو 2026).