M87
[References]
HEGRA: F.A. Aharonian et al., AA 403, L1 (2003)
H.E.S.S.: F. Aharonian et al. Science 314, 1424-1427 (2007)
M.Beilicke et al., 30th ICRC (2007) / arXiv:0710.4057 [astro-ph]
p.118
A. Abramowski
et al., arXiv:arXiv;1111.5341 [astro-ph]
VERITAS:
V.A.
Acciari et al., ApJ 679, 397-403 (2008)
C.M. Hui et
al., ICRC2009 / arXiv:0907.4792 [astro-ph]
V.A. Acciari et al., ApJ 716, 819-824 (2010)
E. Aliu et al., arXiv:1112.4518 [astro-ph]
M. Beilicke et al.,
arXiv:1210.7830 [astro-ph]
MAGIC: J. Albert et al., ApJ 685, L23 (2008)
D. Tescaro et al.,
ICRC2009 / arXiv:0907.0460 [astro-ph] (2009)
K. Berger et al.,
ICRC2011 / arXiv:1109.5879 [astro-ph]
J. Aleksic et al.,
arXiv:1207.2147 [astro-ph]
V.A. Acciari et al.,
arXiv:2001.01643 [astro-ph]
VERITAS/VLBA/HESS/MAGIC: Scinece, 24, 444-448 (2009)