Attribution-NonCommercial 3.0 United States
This is an open access article, originally published at http://dx.doi.org/10.2147/COPD.S150034
Med mindre annet er angitt, så er denne innførselen lisensiert som Attribution-NonCommercial 3.0 United States This is an open access article, originally published at http://dx.doi.org/10.2147/COPD.S150034