https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-45
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-43
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-44
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-46