Miszalski, B.; Boffin, H. M. J.; Frew, D. J.; Acker, A.; Köppen, J.; Moffat, A. F. J.; Parker, Q. A. (2012). "A barium central star binary in the Type I diamond ring planetary nebula Abell 70". Monthly Notices of the Royal Astronomical Society. 419 (1): 39–49. arXiv:1108.3957. Bibcode:2012MNRAS.419...39M. doi:10.1111/j.1365-2966.2011.19667.x.
Miszalski, B.; Boffin, H. M. J.; Frew, D. J.; Acker, A.; Köppen, J.; Moffat, A. F. J.; Parker, Q. A. (2012). "A barium central star binary in the Type I diamond ring planetary nebula Abell 70". Monthly Notices of the Royal Astronomical Society. 419 (1): 39–49. arXiv:1108.3957. Bibcode:2012MNRAS.419...39M. doi:10.1111/j.1365-2966.2011.19667.x.
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Miszalski, B.; Boffin, H. M. J.; Frew, D. J.; Acker, A.; Köppen, J.; Moffat, A. F. J.; Parker, Q. A. (2012). "A barium central star binary in the Type I diamond ring planetary nebula Abell 70". Monthly Notices of the Royal Astronomical Society. 419 (1): 39–49. arXiv:1108.3957. Bibcode:2012MNRAS.419...39M. doi:10.1111/j.1365-2966.2011.19667.x.