1. University Clinical Centre; Tuzla; Bosnia and Herzegovina
2. Nephrology Kantonsspital Aarau; Aarau; Switzerland
3. Fresenius Dialysis Centre; Esztergom; Hungary
4. Fresenius Dialysis Centre Erzsebet Hospital; Sopron; Hungary
5. Fresenius Dialysis Centre; Semmelweis University; Budapest; Hungary
6. University Clinical Centre; Uppsala; Sweden
7. Nephrology; Lapeyronie University Hospital; Montpellier; France
8. Clinical Research; Fresenius Medical Care; Bad Homburg; Germany