1. Department of Theoretical Physics and Astrophysics, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
2. Nicolaus Copernicus Astronomical Center, Bartycka 18, PL-00-716 Warsaw, Poland
3. Instytut Astronomiczny, Uniwersytet Wrocławski, PL-51-622 Wrocław, Poland
4. American Association of Variable Star Observers (AAVSO), Cambridge, USA
5. Bundesdeutsche Arbeitsgemeinschaft für Veränderliche Sterne e.V. (BAV), Berlin, Germany
6. Institute of Astronomy, University of Vienna, Türkenschanzstrasse 17, A-1180 Vienna, Austria
7. Faculty of Science, P. J. Šafárik University, Park Angelinum 9, Košice 040 01, Slovak Republic
8. Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
9. Astronomical Institute, Slovak Academy of Sciences, 059 60 Tatranská Lomnica, Slovak Republic
10. ICA, Slovak Academy of Sciences, Dubravska cesta 9, 84 503 Bratislava, Slovak Republic