M. M. Rashid, M. M. Khair, M. A. Hossain, and M. R. Hassan, “Newer Effective Treatment for Adult Acute Asthmatics with a Multi-Dose Regimen of Ipratropium Bromide Plus Salbutamol Using Metered Dose Inhalers with a Spacer Device in Emergency Department”, J. Bangladesh Coll. Phys., vol. 30, no. 4, pp. 195–200, Apr. 2013.