1. They have clear evidence that the findings are unreliable, either as a result of misconduct (e.g. data fabrication) or honest error (e.g. miscalculation or

2. the findings have previously been published elsewhere without proper crossreferencing, permission or justification (i.e. cases of redundant publication)

3. it constitutes plagiarism

4. it reports unethical research

The mechanism of retraction follow the Retraction Guidelines of Committee on Publication Ethics (COPE) which can be accessed at https://publicationethics.org/files/retraction%20guidelines.pdf