Song, J-W., et al. “Clinical Course and Outcome of Rheumatoid Arthritis-Related Usual Interstitial Pneumonia”. Sarcoidosis, Vasculitis and Diffuse Lung Diseases, vol. 30, no. 2, Aug. 2013, pp. 103-12, https://mattioli1885journals.com/index.php/sarcoidosis/article/view/3021.