1. Epidemiology, Biostatistics and Prevention Institute; University of Zürich; Zurich Switzerland
2. Institute for Medical Information Processing, Biometry and Epidemiology; Ludwig-Maximilians-Universität München; Munich Germany
3. lnstitute of Clinical Neuroimmunology; Ludwig-Maximilians-Universität München; Munich Germany
4. Pettenkofer School of Public Health; Munich Germany
5. University Library; University of Zurich; Zurich Switzerland
6. Institute of Health Services Research in Dentistry; University of Münster; Muenster Germany
7. IGDORE; Munich Germany