1. Ruhr-University, Bochum, Germany, Johannes-Gutenberg-University, Mainz, Germany,
2. Ruhr-University, Bochum, Germany
3. Johannes-Gutenberg-University, Mainz, Germany
4. Universidad de Valencia, Spain
5. Queen's University, Kingston, ON, Canada
6. Psychosomatic Clinic, St. Franziska-Stift, Bad Kreuznach, Germany, University of Trier, Trier, Germany