1. Department of Mathematics, University of Warwick, CV4 7AL Coventry, United Kingdom
2. Department of Physical Chemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
3. Radon Institute for Computational and Applied Mathematics, Austrian Academy of Sciences, Altenberger Strasse 69, 4040 Linz, Austria
4. Institute for Computational and Applied Mathematics, WWU Münster, Münster 48149, Germany
5. Institute of Advanced Studies Kőszeg (iASK), Chernel st. 14. H-9730 Kőszeg, Hungary