Effectiveness of controlled breathing techniques on anxiety and depression in hospitalized patients with COPD: A randomized clinical trial
Valenza MC, Valenza-Peña G, Torres-Sánchez I, González-Jiménez E, Conde-Valero A, Valenza-Demet G. Effectiveness of controlled breathing techniques on anxiety and depression in hospitalized patients with COPD: A randomized clinical trial. Respir Care. 2014 Feb;59(2):209-15