1. Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital – 263002, India
2. Institute of Astronomy and National Astronomical Observatory,Bulgarian Academy of Sciences, 72 Tsarigradsko Shosse Blvd., 1784 Sofia, Bulgaria
3. Department of Physics, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628-0718, USA
4. Abastumani Observatory, Mt. Kanobili, 0301 Abastumani, Georgia
5. Engelhardt Astronomical Observatory, Kazan Federal University, Tatarstan, Russia
6. Center for Astrophysics, Guangzhou University, Guangzhou, 510006, China
7. Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany
8. American Association of Variable Star Observers (AAVSO), 49 Bay State Rd., Cambridge, MA 02138, USA
9. Group M1, Centro Astronómico de Avila, Madrid, Spain
10. Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia
11. Department of Physics and Astronomy, Faculty of Natural Sciences, University of Shumen, 115, Universitetska Str., 9700 Shumen, Bulgaria