1. Network Aging Research, Heidelberg University, Germany
2. Mixed Methods Research, Heidelberg University of Education, Germany
3. Division of Sociology, Social Policy and Social Work, University of Fribourg, Switzerland
4. Center of Competence for Gerontology, University of Zurich, Switzerland
5. Department of Special Education and Rehabilitation Science, Chair of Rehabilitative Gerontology, University of Cologne, Germany