K. Haj Hammo, M., J. Al layla, D., & M. A. Al Hayali, R. (2006). Prevalence of gastro-oesophageal reflux symptoms in patients with COPD. Annals of the College of Medicine, Mosul, 32(1), 18–22. https://doi.org/10.33899/mmed.2006.30122