1. Ragnar Nurkse Department of Innovation and Governance, Tallinn University of Technology (TalTech), Akadeemia Tee 3, 12618 Tallinn, Estonia
2. EurA AG, 99084 Erfurt, Germany
3. Polycare Research Technology GmbH, 98528 Gehlberg, Germany
4. Independent Researcher, 13403 Berlin, Germany