https://aoemj.biomedcentral.com/articles/10.1186/s40557-014-0021-4
https://aoemj.biomedcentral.com/articles/10.1186/s40557-014-0026-z
https://aoemj.biomedcentral.com/articles/10.1186/s40557-014-0025-0
https://aoemj.biomedcentral.com/articles/10.1186/s40557-014-0028-x