1. Institute for Mathematical Stochastics; University of Göttingen; Göttingen Germany
2. Max Planck Institute for Biophysical Chemistry; Göttingen Germany
3. Department of Mathematics; University of Innsbruck; Innsbruck Austria
4. Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie; Göttingen Germany