Mahmood, A., F. Rashid, D. Hawkes, W. J. Harrison, and CHIP Collaborative Group. “Coronavirus in HIP Fractures CHIP 2: Is Vitamin D Deficiency Associated With Increased Mortality from COVID-19 Infections in A Hip Fracture Population?”. European Journal of Medical and Health Sciences 3, no. 6 (December 29, 2021): 111–116. Accessed August 14, 2022. https://www.ej-med.org/index.php/ejmed/article/view/1159.