Uzma Afreen, Mubushra Samina, Shaima Sultana Memon, Hafiz Syed Muhammad Osama Jafri, Sumaira Riffat, Saba Abrar. “Relationship Between Serum 25-Hydroxy Vitamin D Level and Menstrual Cycle Irregularity: A Cross-Sectional Study”. Pakistan Journal of Medical & Health Sciences, vol. 16, no. 11, Jan. 2023, p. 511, doi:10.53350/pjmhs20221611511.