The editors or editorial board must ensure that all research manuscripts are reviewed. They select study reviewers for peer review procedure, which is anonymous. Each manuscript is always assessed by two independent reviewers, who are usually specialists in field of study and who must not be employees at same institution as the author of the manuscript, or project colleagues. The manuscripts will be only published, if the reviewers come to the positive assessments and all their comments are worked out. If both assessments are negative, the editorial board have to decide to reject the study and inform the author about this situation. In case of different assessments the manuscript is given to a third reviewer for assessment.