[1] Richard Stone. Science, 2008, 320(4): 34.
[2] Goebel J, Stutz J, Volk K, et al. Astronomy and Astrophysics, 1989, 222: 5.
[3] Gulati R K, Gupta R, Gothoskar P. Astrophysical Journal, 1994, 426(1): 340.
[4] Bailer-Jones C A L. Astronomy and Astrophysics, 2000, 357: 197.
[10] Zhang Jifu, Li Yinhua, Zhang Sulan. High Technology Letters, 2007, 13(4): 422.