“A Randomized Double-Blinded Superiority Trial to Compare the Efficacy of Vitamin D3 and Calcium Versus Placebo in Prevention of Hip Fractures in Elderly Women”. Principles and Practice of Clinical Research 2, no. 1 (March 15, 2016). Accessed May 1, 2024. https://journal.ppcr.org/index.php/ppcrjournal/article/view/27.