galaxie de Seyfert
1976 / Seyfert galaxies, quasars and redshifts / Daniel W. Weedman / Quarterly Journal of the Royal Astronomical Society 17 (1976) p. 227 [lien]
1977 / Seyfert Galaxies / Daniel W. Weedman / Annual Review of Astronomy and Astrophysics 15 (1977) p. 69 [doi]