Annesi-Maesano, I., et al. “Epidemiology of Idiopathic Pulmonary Fibrosis in Europe – an Update”. Sarcoidosis, Vasculitis and Diffuse Lung Diseases, vol. 30, no. Suppl 1, Sept. 2013, pp. 6-12, https://mattioli1885journals.com/index.php/sarcoidosis/article/view/3091.