Acknowledgement
We would like to thank Prof. Dr. Sreten Andonov, Dr. Andreas Hoppe, Mr. Thomas Galea, Dr. Marin Kovačić, Mr. Egoitz Galarza and Prof. Dr. Kaspar Bienefeld for their valuable comments and suggestions for improvement of the readability of the article. We also thank Mr. Dejan Madjirov for the graphical design of .
Disclosure statement
No potential conflict of interest was reported by the authors.