https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-15-8
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-15-11
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-15-15
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-15-9
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-15-12
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-15-13