1. International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk 630090 (Russia), Fax: (+7) (383)333‐1399
2. Novosibirsk State University, Pirogova 2, Novosibirsk 630090 (Russia)
3. Freie Universität Berlin, Arnimallee 14, Berlin, 14195 (Germany)
4. Utrecht University, Bijvoet Center, Padualaan 8, NL‐3584 CH, Utrecht (The Netherlands), Fax: (+31) (30)2537623