Rizka, A., S. Setiati, K. Harimurti, M. Sadikin, and I. G. Mansur. “Effect of Alfacalcidol on Inflammatory Markers and T Cell Subsets in Elderly With Frailty Syndrome: A Double Blind Randomized Controlled Trial”. Acta Medica Indonesiana, vol. 50, no. 3, Oct. 2018, p. 215, https://www.actamedindones.org/index.php/ijim/article/view/622.