Pant P, Yadav B, Khan G, Koju R, Gurung R, Pokharel B, Bedi T, Adkhari R. Role of tiotropium in chronic obstructive pulmonary disease exacerbation. Journal of Institute of Medicine [Internet]. 2011 Jun. 24 [cited 2024 May 3];32(2):5-10. Available from: https://www.nepjol.info/index.php/JIOM/article/view/4937