Z. Kirovakov, M. Obreykova, N. Kostadinov, A. Jovanovska-Kirovakova, and E. Gyokova, “Association between serum vitamin D, insulin resistance (HOMA-IR), and gestational diabetes mellitus”, AMB, vol. 53, no. 3, pp. 48–54, Sep. 2026, doi: 10.2478/AMB-2026-0072.