Abramowski A., Acero F., Aharonian F., Akhperjanian A.G, Anton G., Balzer A., Barnacka A., U. de Almeida B, Becherini Y., Becker J. et al..  2012.  The 2010 Very High Energy $\gamma$-Ray Flare and 10 Years of Multi-wavelength Observations of M 87}. The Astrophysical Journal. 746:151.

Aleksi? J., Alvarez E.A, Antonelli L.A, Antoranz P., Asensio M., Backes M., U. de Almeida B, Barrio J.A, Bastieri D., J. González B et al..  2012.  Detection of very-high energy $\gamma$-ray emission from NGC 1275 by the MAGIC telescopes}. Astronomy and Astrophysics. 539:L2.

Aleksi? J., Antonelli L.A, Antoranz P., Backes M., Barrio J.A, Bastieri D., J. González B, Bednarek W., Berdyugin A., Berger K. et al..  2011.  MAGIC Discovery of Very High Energy Emission from the FSRQ PKS 1222+21. The Astrophysical Journal Letters. 730:L8.