https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-37
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-40
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-41
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-39
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-38
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-5-42