https://bmcmedinformdecismak.biomedcentral.com/articles/10.1186/1472-6947-11-56
https://bmcmedinformdecismak.biomedcentral.com/articles/10.1186/1472-6947-11-55
https://bmcmedinformdecismak.biomedcentral.com/articles/10.1186/1472-6947-11-57