1. Global Strategy for Diagnosis, Management, and Prevention of COPD from the Global Initiative for Chronic Obstructive Lung Disease (GOLD). 2013. http://www.goldcopd.org/ (accessed 12 May 2014).
2. Da Cas R , Ruggeri P , Rossi M, et al. Prescrizione farmaceutica in Umbria. Analisi dei dati relativi al 2011. Rapporti ISTISAN 13/11. Roma: Istituto Superiore di Sanità; 2013:1–133.
3. Spiriva® Summary of Product Characteristics. Banca dati farmaci. Agenzia Italiana del Farmaco. https://farmaci.agenziafarmaco.gov.it/aifa/pages/home.jsp (accessed 12 May 2014).
4. Spiriva® Respimat® Summary of Product Characteristics. Banca dati farmaci. Agenzia Italiana del Farmaco. https://farmaci.agenziafarmaco.gov.it/aifa/pages/home.jsp (accessed 12 May 2014).
5. Use of Respimat Soft Mist inhaler in COPD patients;Anderson;Int J Chron Obstruct Pulmon Dis,2006