1. Allen, G.E., Houck, J.C., Sturner, S.J.: in On-line Proceedings of the X-ray and Radio Connections workshop, Sante Fe, New Mexico. [http://www.aoc.nrao.edu/events/xraydio] (2004)
2. Amati, E., Blasi, P.: MNRAS 3711251 (2006)
3. Anderson, M.C., Keohane, J.W., Rudnick, L.: ApJ 441300 (1995)
4. Bamba, A., Yamazaki, R., Ueno, M., Koyama, K.: ApJ 589827 (2003)
5. Baring, M.G.: in Proc. of the 26th International Cosmic Ray Conference, Vol. IV, p. 5, held in Salt Lake City, Utah [astro-ph/9910128] (1999)