Lesmana, A., Tarigan, A. P. and Syarani, F. (2019) “Effectiveness of administration of bronchodilator by spacers, home-made spacers and nebulizers in patients with chronic obstructive pulmonary disease”, International Journal of Research in Medical Sciences, 7(6), pp. 2417–2421. doi: 10.18203/2320-6012.ijrms20192540.