Hidayat, M., K. R. Wardani, B. M. Purba, and R. T. Apreza. “Blood Calcium Level and Its Correlation With Calcium Daily Intake, Calcium Supplementation &Amp; Clinical Symptoms in Women With Premenstrual Syndrome”. Journal of Medicine and Health, vol. 1, no. 6, Aug. 2017, doi:10.28932/jmh.v1i6.556.