Chandran, Manju, et al. “Vitamin D Levels, Physical and Biochemical Characteristics of South East Asian Patients With Osteoporotic Hip Fractures”. Journal of the ASEAN Federation of Endocrine Societies, vol. 27, no. 2, May 2014, p. 185, https://asean-endocrinejournal.org/index.php/JAFES/article/view/35.