@article {K{\"o}hler825, author = {D K{\"o}hler and J Fischer and F Raschke and B Sch{\"o}nhofer}, title = {Usefulness of GOLD classification of COPD severity}, volume = {58}, number = {9}, pages = {825--825}, year = {2003}, doi = {10.1136/thorax.58.9.825}, publisher = {BMJ Publishing Group Ltd}, issn = {0040-6376}, URL = {https://thorax.bmj.com/content/58/9/825.1}, eprint = {https://thorax.bmj.com/content/58/9/825.1.full.pdf}, journal = {Thorax} }