Hale Karapolat, et al. “The Relationship Between Bath Indexes and Osteoporosis in Male Patients With Axial Ankylosing Spondylitis”. Archives of Rheumatology, vol. 23, no. 3, Sept. 2008, pp. 082-6, http://www.anadolupsikiyatri.net/index.php/pub/article/view/255.