TY - JOUR AU - Köhnlein, T; Windisch, W; Köhler, D TI - Non-invasive positive pressure ventilation for the treatment of severe stable chronic obstructive pulmonary disease: a prospective, multicentre, randomised, controlled clinical trial JO - Lancet Respir Med VL - 2 PY - 2014 DO - 10.1016/S2213-2600(14)70153-5 SP - 698 EP - 705 N1 - et al. ER -