A phase III randomized controlled trial of tiotropium add-on therapy in children with severe symptomatic asthma.
Szefler SJ, Murphy K, Harper T, Boner A, Laki I, Engel M, El Azzi G, Moroni-Zentgraf P, Finnigan H, Hamelmann E. A phase III randomized controlled trial of tiotropium add-on therapy in children with severe symptomatic asthma. J Allergy Clin Immunol. 2017 Nov; 140(5):1277-1287.