[1
]
1 University Hospital Aintree Liverpool, United Kingdom.
[2
]
2 Boehringer Ingelheim Pharma GmbH & Co. KG Ingelheim, Germany.
[3
]
3 University of Tübingen Tübingen, Germany.
[4
]
4 University Medical Center Giessen and Marburg, Philipps-Universität Marburg Marburg,
Germany.
[5
]
5 University of Modena and Reggio Emilia Modena, Italy.
[6
]
6 Lung Clinic Grosshansdorf, Airway Research Center North Grosshansdorf, Germany.
[7
]
7 Maastricht University Medical Center Maastricht, the Netherlands and.
[8
]
8 Boehringer Ingelheim Bracknell, United Kingdom.