1. Physikalisch-Technische Bundesanstalt (PTB)
2. D-10587 Berlin
3. Germany
4. LGC Ltd.
5. Teddington
6. UK
7. Institute for Reference Materials and Measurements (IRMM)
8. Joint Research Centre (JRC)
9. European Commission
10. 2440 Geel
11. Belgium
12. Analytical Sciences
13. National Physical Laboratory
14. Biological Nanochemistry Research Group
15. Institute of Materials and Environmental Chemistry
16. Research Centre for Natural Sciences
17. Hungarian Academy of Sciences
18. 1117 Budapest