Orlando, E. High Energy Astrophysics, MPI for Extraterrestrial Physics, Max Planck Society;
The Fermi-LAT Collaboration, Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., et al. (2010). Fermi gamma-ray imaging of a radio galaxy. Science, 328(5979), 725-729. doi:10.1126/science.1184656.