1. P. R. Wozniak, W. T. Vestrand, C. W. Akerlof, et al., Northern Sky Variability Survey: Public Data Release, Astron. J. 27, 2436 (2004).
2. S. A. Otero, R. Wils, G. Hoogeveen, and P. A. Dubovsky, Inf. Bul. Var. Stars 5681, 1 (2006).
3. V. S. Kozyreva, A. V. Kusakin, and J. Menke, Inf. Bul. Var. Stars 6020, 1 (2012).
4. V. G. Kornilov, I. M. Volkov, and A. I. Zakharov, et al.: Catalog of WBVR-stars in the Northern Sky, Proc. Sternberg Institute of Astronomy 63 (1991).
5. A. Pickles, Publ. Astron. Soc. Pacif. 110, 863 (1998).