https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-10
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-12
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-14
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-11
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-13