Sakelliou, Irini; Hardcastle, M. J.; Jetha, N. N. (Şubat 2008). "3C 40 in Abell 194: can tail radio galaxies exist in a quiescent cluster?". Monthly Notices of the Royal Astronomical Society. 384 (1). ss. 87-93. arXiv:0709.2133 $2. doi:10.1111/j.1365-2966.2007.12465.x.
Sakelliou, Irini; Hardcastle, M. J.; Jetha, N. N. (Şubat 2008). "3C 40 in Abell 194: can tail radio galaxies exist in a quiescent cluster?". Monthly Notices of the Royal Astronomical Society. 384 (1). ss. 87-93. arXiv:0709.2133 $2. doi:10.1111/j.1365-2966.2007.12465.x.