https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0663-z
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0667-8
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0673-x
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0662-0
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0668-7
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0660-2
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0672-y
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0670-0
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0661-1
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0677-6
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0664-y
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0659-8
https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-018-0665-x