After a very good acceptance of the first two issues, in front of you there is the third issue of the internationally reviewed multidisciplinary scientific journal “ST-OPEN“, published by the University of Split. ST-OPEN is an overlay+ journal open to students and teachers from the University of Split and other universities in Croatia and globally. In this issue, we continue with our author-helpful policy in order to transform graduate theses into scientific papers and translate them into English without any cost to the authors. All articles are published in a diamond open access form on a continuous basis using the online first publishing principle, which allows readers access to the articles well before the whole volume is completed.