https://health-policy-systems.biomedcentral.com/articles/10.1186/1478-4505-8-31
https://health-policy-systems.biomedcentral.com/articles/10.1186/1478-4505-8-33
https://health-policy-systems.biomedcentral.com/articles/10.1186/1478-4505-8-29
https://health-policy-systems.biomedcentral.com/articles/10.1186/1478-4505-8-30
https://health-policy-systems.biomedcentral.com/articles/10.1186/1478-4505-8-32