“Effects of Home Air Purifiers in the Quality of Life of Patients With Chronic Obstructive Pulmonary Disease in Mexico City: : A Phase III, Single-Center, Triple-Blinded, Randomized Controlled Trial (GREAT-COPD)”. Principles and Practice of Clinical Research 8, no. 1 (April 24, 2022): 9–15. Accessed October 15, 2024. https://journal.ppcr.org/index.php/ppcrjournal/article/view/181.