https://human-resources-health.biomedcentral.com/articles/10.1186/1478-4491-12-33
https://human-resources-health.biomedcentral.com/articles/10.1186/1478-4491-12-35
https://human-resources-health.biomedcentral.com/articles/10.1186/1478-4491-12-32
https://human-resources-health.biomedcentral.com/articles/10.1186/1478-4491-12-34
https://human-resources-health.biomedcentral.com/articles/10.1186/1478-4491-12-36