https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0153-4
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0149-0
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0156-1
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0151-6
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0154-3
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0155-2