1. Department of Dermatology, University of Bonn, Bonn, Germany
2. Practice for Vascular Medicine, Tegernsee, Germany
3. Vascular Unit, Poliambulatorio Hippocrates and Clinic Stella Maris, San Benedetto del Tronto (AP), Italy
4. British Vein Institute, London, UK
5. Studio Medico Flebologico – Figline Valdarno, Florence, Italy
6. Vascular Medicine and Phlebology, Bourgoin-Jallieu, France
7. Cabinet de Phlébologie, Nice, France
8. Department of Vascular Medicine, Saint Martin Private Hospital, Caen, France
9. Private office Vevey, Service of Angiology, Lausanne University Hospital, Lausanne, Switzerland
10. Private Practice, Vienna, Austria
11. Department of Dermatology, University of Bern, Switzerland
12. Bassi Foundation Trieste, Italy
13. Department of Dermatology, University of Cologne, Cologne, Germany