https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-7
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-9
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-6
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-8
https://ij-healthgeographics.biomedcentral.com/articles/10.1186/1476-072X-7-10