Roflumilast in moderate-to-severe chronic obstructive pulmonary disease treated with longacting bronchodilators: two randomised clinical trials

1. Fabbri, L.M.
2. Calverley, P.M.
3. Izquierdo-Alonso, J.L.
4. Bundschuh, D.S.
5. Brose, M.
6. Martinez, F.J.
7. Rabe, K.F.