https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-42
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-44
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-46
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-41
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-43
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-47
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-40
https://bmcsurg.biomedcentral.com/articles/10.1186/1471-2482-14-45