Journal Article
Caballero, Andres, Carlos A Torres-Duque, Claudia Jaramillo, Fabio Bolivar, Fernando Sanabria, Patricia Osorio, Carlos Orduz, Diana P Guevara, and Dari´o Maldonado.
"Prevalence of COPD in five Colombian cities situated at low, medium, and high altitude (PREPOCOL study)." CHEST Journal 133, no. 2 (2008): 343-349.