Vela Lozada, MD., F. and Celis Preciado, MD., C. 2012. Combined therapy of prednisone, azathioprine and acetylcysteine increases the risks of death and hospitalization in pulmonary fibrosis: the importance of a negative trial. Revista Colombiana de Neumología. 24, 4 (Dec. 2012), 214–215. DOI:https://doi.org/10.30789/rcneumologia.v24.n4.2012.146.