https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-39
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-40
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-38
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-35
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-37
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-9-36