1. , Germany
2. BAM
3. Federal Institute for Material Research and Testing
4. D-12489 Berlin, Germany
5. 3MTechnical Ceramics Kempten
6. Zweigniederlassung der 3M Deutschland GmbH
7. Kempten, Germany
8. Institute of General and Inorganic Chemistry
9. Bulgarian Academy of Sciences
10. BG-1113 Sofia, Bulgaria
11. SPECTRO Analytical Instruments GmbH
12. 47533 Kleve, Germany