1. From the Global Strategy for the Diagnosis, Management and Prevention of COPD, Global. Initiative for Chronic Obstructive Lung Disease (GOLD) 2008. [consultado 1/2/2009]. Disponible en: http://www.goldcopd.org.
2. Effects of smoking intervention and the use of an inhaled anticholinergic bronchodilatador on the rate of decline of FEV1. The Lung Health Study;Anthonisen;JAMA,1994
3. Prevalence of COPD in Spain: impact of undiagnosed COPD on quality of life and daily life activities;Miravitlles;Thorax,2009
4. Atención integral al paciente con enfermedad pulmonar obstructiva crónica (EPOC). Desde la Atención Primaria a la Especializada. [consultado 10/9/2010]. Disponible en: http://www.guiasalud.es/viewGPC.asp?idGuia=468.
5. Agency for Healthcare Research and Quality. Use of spirometry for case finding, diagnosis, and management of chornic obstructive pulmonary disease (COPD), AHRQ PublicationNo.05-E017-2,2005. [consultado 11/9/2010]. Disponible en:http://www.ahrq.gov/downloads/pub/evidence/pdf/spirocopd/spiro.pdf.