Open Access Statement

All journal content is freely available without charge to the user or his/her institution. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles in this journal without asking prior permission from the publisher or the author, with due acknowledgement (citation) to authors and the journal.

Also, editorial staff encourages the authors: - to post the final version of the article on their personal webpage or on that of the institution to which they officially belong; -to post on the pages they manage the link to the PDF version of the article hosted on journal website. -the authors may use without any restrictions the article in their teaching and research activities.