Table 1.

Reasons for papers’ retraction adapted from COPE guidelines [2]

Reason	Definition
Redundant publication	Publication of the same data or article in more than one journal without appropriate justification, permission or cross-referencing
Overlap	Some new findings are presented in an article that also contains a substantial amount of previously published information
Misconduct	Evidence of unreliable results caused, for example, by data fabrication
Honest error	Evidence of unreliable results, caused, for example, by a miscalculation or by an experimental error
Plagiarism	Content of other author (data, words or theories) is presented by another author without referencing as it was his own
Authorship issues	Authorship dispute of an article
No reason reported	No clear information of the reasons for the retraction was mentioned