https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-30
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-28
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-29
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-32
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-31