BL Lac

[References]

Whipple: M. Catanese et al., Astrophys. J. 480, 562 (1997) [Upper limit] / astro-ph/0311397 [correction]

HEGRA: F.A. Aharonian et al., Astron. Astrophys. 353, 847-852 (2000) [Upper limit]

Crimea: Neshpor, Yu. I. et al., Astronomy Reports, 45, 249-254 (2001)

MAGIC: J. Albert et al., astro-ph/0703084
           M. Hayashida et al., 30th ICRC (2007) / arXiv:0709.2265 [astro-ph]
           V.A. Acciari et al., arXiv:1901.01733 [astro-ph]

VERITAS: M. Arken et al., arXiv:1211.3074 [astro-ph]
               A. U. Abeysekara et al. arXiv:1802.10113 [astro-ph]