1. Kempf und Pfaltz; Histologische Diagnostik; Zürich Switzerland
2. Department of Dermatology; University Hospital Zürich; Zürich Switzerland
3. Department of Pathology; Medical Faculty in Pilsen; Charles University in Prague; Prague Czech Republic
4. Department of Dermatology; Medical Military Academy; Saint-Petersburg Russia
5. Department of Dermatology; HELIOS-Klinikum; Hildesheim Germany