https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-8-16
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-8-13
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-8-14
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-8-15
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-8-17