HAMEED, ABDUL, et al. “EFFECT OF ORAL AND INJECTABLE CONTRACEPTIVES ON SERUM CALCIUM, MAGNESIUM AND PHOSPHORUS IN WOMEN”. Journal of Ayub Medical College Abbottabad, vol. 13, no. 3, Aug. 2001, pp. 24-25, https://jamc.ayubmed.edu.pk/index.php/jamc/article/view/4871.