Kawkitinarong, K., Ananpipatkul, A., Sae-Eao, N., Asawawichienchinda, T. and Sirichana, W. 2021. Effects of fenoterol/ipratropium bromide on FEV1 and hyperinflation in Thai COPD patients. Chulalongkorn Medical Journal. 65, 2 (Apr. 2021).