The Editor and Associate Editors would like to thank 166 colleagues from 28 different countries representing Europe, North America, South America, and Asia who acted as reviewers of the articles submitted to the 34th volume, both for agreeing to read the manuscripts and for the advice they offered to authors. The quality of the volume reflects their competence and the value of their judgment. We would like to thank especially those colleagues who are not members of the Editorial Board of the journal.