1. Harstall C, Ospina M. How prevalent is chronic pain? Pain Clinical Updates [Internet]. 2003, 11:1–4. Available at http://www.iasp-pain.org/AM/AMTemplate.cfm?Section=Home&CONTENTID=7594&TEMPLATE=/CM/ContentDisplay.cfm&SECTION=Home . Accessed April 2013.
2. Azevedo L, Costa-Pereira A, Mendonça L, et al. Epidemiology of chronic pain: a population-based nationwide study on its prevalence, characteristics and associated disability in Portugal. J Pain. 2012;13:773–83.
3. Ablin J, Oren A, Cohen S, et al. Prevalence of fibromyalgia in the Israeli population: a population-based study to estimate the prevalence of fibromyalgia in the Israeli population using the London Fibromyalgia Epidemiology Study Screening Questionnaire (LFESSQ). Clin Exp Rheumatol. 2012;30 Suppl 74:39–43.
4. Neumann L, Buskila D. Epidemiology of fibromyalgia. Curr Pain Headache Rep. 2003;7:362–8.
5. White K, Harth M. Classification, epidemiology, and natural history of fibromyalgia. Curr Pain Headache Rep. 2001;5:320–9.