https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-00216-w
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-00217-9
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-00220-0
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-00219-7