«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), с. 53–57. доступний у: https://ojshostng.com/index.php/ajbr/article/view/1689 (дата звернення: 26 Червень 2026).