https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0174-z
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-017-0180-9
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0178-8
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-017-0186-3
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0175-y
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-017-0183-6
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-017-0181-8
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0177-9
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-016-0176-x
https://human-resources-health.biomedcentral.com/articles/10.1186/s12960-017-0182-7