PG 1553+113
[References]
H.E.S.S.: F. Aharonian et al. Astron. Astrophys. 448, L19-L23 (2006)
F. Aharonian et al. Astron. Astrophys. 477,
481-489 (2008)
W.Benbow et al., 30th ICRC (2007) / arXiv:0710.4057 [astro-ph]
p.126
MAGIC: J. Albert et al., Astrophys. J. Lett. 654, L119-L122 (2007)
J. Albert et al.,
arXiv:0812.3037 [astro-ph]