Komossa, Stefanie (April 2008). "Narrow-Line Seyfert 1 Galaxies". Revista Mexicana de Astronomía y Astrofísica, Serie de Conferencias. 32: 86–92. arXiv:0710.3326. Bibcode:2008RMxAC..32...86K.
Bekhti, Nadya Ben; Winkel, Benjamin; Richter, Philipp; Kerp, Jürgen; Klein, Ulrich (September 2011). "On the Origin of Gaseous Galaxy Halos – Low-Column Density Gas in the Milky Way Halo". In von Berlepsch, Regina (ed.). Zooming In: The Cosmos at High Resolution. Annual Meeting of the Astronomische Gesellschaft. University of Bonn. 15–16 September 2010. Reviews in Modern Astronomy. Vol. 23. John Wiley & Sons. pp. 117–130. arXiv:1102.5205. doi:10.1002/9783527644384.ch7. ISBN9783527411139.
Bolton, J. G.; Stanley, G. J. (1948). "Observations on the Variable Source of Cosmic Radio Frequency Radiation in the Constellation of Cygnus". Australian Journal of Scientific Research A. 1: 58–69. Bibcode:1948AuSRA...1...58B. doi:10.1071/ch9480058.
de Vancouleurs, G.; de Vancouleurs, A. (1968). Photographic, Photometric, and Spectroscopic Observations of Seyfert Galaxies. Proceedings of the Conference on Seyfert Galaxies and Related Objects. 14–16 February 1968. University of Arizona. The Astronomical Journal. Vol. 73, no. 9. pp. 858–861. Bibcode:1968AJ.....73..858D. doi:10.1086/110717.
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Bekhti, Nadya Ben; Winkel, Benjamin; Richter, Philipp; Kerp, Jürgen; Klein, Ulrich (September 2011). "On the Origin of Gaseous Galaxy Halos – Low-Column Density Gas in the Milky Way Halo". In von Berlepsch, Regina (ed.). Zooming In: The Cosmos at High Resolution. Annual Meeting of the Astronomische Gesellschaft. University of Bonn. 15–16 September 2010. Reviews in Modern Astronomy. Vol. 23. John Wiley & Sons. pp. 117–130. arXiv:1102.5205. doi:10.1002/9783527644384.ch7. ISBN9783527411139.
Bolton, J. G.; Stanley, G. J. (1948). "Observations on the Variable Source of Cosmic Radio Frequency Radiation in the Constellation of Cygnus". Australian Journal of Scientific Research A. 1: 58–69. Bibcode:1948AuSRA...1...58B. doi:10.1071/ch9480058.
de Vancouleurs, G.; de Vancouleurs, A. (1968). Photographic, Photometric, and Spectroscopic Observations of Seyfert Galaxies. Proceedings of the Conference on Seyfert Galaxies and Related Objects. 14–16 February 1968. University of Arizona. The Astronomical Journal. Vol. 73, no. 9. pp. 858–861. Bibcode:1968AJ.....73..858D. doi:10.1086/110717.
Adams, Thomas F. (1977). "A Survey of the Seyfert Galaxies Based on Large-Scale Image-Tube Plate". The Astrophysical Journal Supplement. 33: 19–34. Bibcode:1977ApJS...33...19A. doi:10.1086/190416.
Komossa, Stefanie (April 2008). "Narrow-Line Seyfert 1 Galaxies". Revista Mexicana de Astronomía y Astrofísica, Serie de Conferencias. 32: 86–92. arXiv:0710.3326. Bibcode:2008RMxAC..32...86K.
Halliday, Ian (1969). "Advances in Astronomy Seyfert Galaxies and Quasars". Journal of the Royal Astronomical Society of Canada. 63: 91. Bibcode:1969JRASC..63...91H.