1. Dermatology Centre Parmova & DCP-Venex Centre, Ljubljana, Slovenia
2. VENEX Vein Centre, Vienna, Austria
3. University Hospital of Grenoble, Grenoble, France
4. Department of Dermatology, University of Bonn, Bonn, Germany
5. Dr. Maurins Vein Clinic, Riga, Latvia
6. Morrison Vein Institute, AZ, USA
7. Department of Dermatology, University of Cologne, Köln, Germany