1. M. G. Abramyan, Astrofizika 52, 135 (2009).
2. M. G. Abramyan and L. I. Matveyenko, Astrofizika 55, 397 (2012).
3. H. Arp, Astrophys. J. Lett. 1, 1 (1967).
4. J. A. Biretta, F. Zhou, and F. N. Jwen, Astrophys. J. 447, 582 (1995).
5. P. E. Hardee, in Proceedings of the Conference on Relativistic Jets, the Common Physics of AGN, Microquasars, and Gamma-Ray Bursts, Ann Arbor, Michigan, December 14–17, 2005, Ed. by P. A. Hughes and J. N. Bregman, AIP Conf. Proc. 856, 55 (2006).