https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-11-27
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-11-29
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-11-14
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-11-26
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-11-30
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-11-28