1. S. A. Otero, P. Wils, G. Hoogeveen, and P. A. Dubovsky, Inform. Bull. Var. Stars, No. 5681, 1 (2006).
2. P. R. Wozniak, W. T. Vestrand, C. W. Akerlof, R. Balsano, et al., Astron. J. 127, 2436 (2004).
3. E. V. Kazarovets, N. N. Samus, O. V. Durlevich, N. N. Kireeva, and E. N. Pastukhova, Inform. Bull. Var. Stars, No. 6052, 1 (2013).
4. I. Bulut and O. Demircan, Mon. Not. R. Astron. Soc. 378, 179 (2007).
5. I. M. Volkov and N. S. Volkova, Astron. Rep. 53, 136 (2009).