NGC 253
[References]
CANGAROO-II: Itoh, C. et al., Astronomy and Astrophysics 396, L1-L4
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Itoh, C. et al., Astronomy and
Astrophysics, 402, 443-455 (2003)
Erratum: Itoh, C. et al., Astron. Astrophys.
462, 67-71 (2007)
H.E.S.S.: Aharonian, F. et al., Astron. Astrophys. 442, 177-183 (2005) [upper limit]
D.Nedbal et al., 30th ICRC (2007) / arXiv:0710.4057 [astro-ph]
p.181 [upper limit]
F. Acero et
al., Science 326, 1080-1082 (2009)
A. Abramowski
et al., Astrophys. J. 757:158 (12pp) (2012)
H. Abdalla
et al., arXiv: 1806.03866 [astro-ph]