Funding for this research was provided by:
Economic Development and Innovation Operative Program Grant (GINOP 2.3.2-15- 2016-00048)
Human Resources Development Operational Programme Grant (EFOP-3.6.2-16-2017-00006)
Higher Education Institutional Excellence Programme Grant of the Ministry for Innovation and Technology in Hungary within the framework of the second thematic programme of the University of Pécs (2)
Received: 9 December 2019
Accepted: 17 March 2020
First Online: 17 August 2020
Compliance with ethical standards
: The authors declare that they have no completing interests.
: As it is a systematic review of retrospective studies of the literature, we only processed retrospective data found in the literature by searching online databases. We have not involved human participants and/or animals for this study.
: For these types of articles, there is no need for ethical permissions, informed consents.