Donel S., Inayah, R. A. D. . Putri, M. Y. . Hamidy, M. . Savira, and N. S. . Soraya. “Study of Vitamin D Deficiency on Pregnancy Women in Rupat Utara District Bengkalis Regency Riau Province”. Nusantara Science and Technology Proceedings, Dec. 2022, pp. 94-96, doi:10.11594/nstp.2022.2819.