1. Ludwig-Maximilians-Universität München, Department of Psychology, Germany & Dar es Salaam University College of Education, University of Dar es Salaam, Tanzania
2. Ludwig-Maximilians-Universität München, Department of Psychology, Germany & University of Groningen, Department of Educational Sciences, The Netherlands
3. Ludwig-Maximilians-Universität München, Chair of Mathematics Education, Germany
4. University of Auckland, Faculty of Education and Social Work, New Zealand