https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-0201-8
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-00206-y
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-0205-4
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-0203-6
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-00208-w
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-0204-5
https://resource-allocation.biomedcentral.com/articles/10.1186/s12962-020-0202-7