1. T. Abel, P. Anninos, Y. Zhang, M.L. Norman, New Astron. 2, 181 (1997)
2. T. Abel, G.L. Bryan, M.L. Norman, Science 295, 93 (2002)
3. P.A. Abell, J. Allison et al. (LSST Science Collaboration), arXiv e-print ( arXiv:0912.0201 ) (2009)
4. M. Ackermann, M. Ajello et al. (The Fermi-LAT Collaboration), arXiv e-prints ( arXiv:1308.5654 ) (2013)
5. P.A.R. Ade, N. Aghanim et al. (Planck Collaboration), arXiv e-prints ( arXiv:1303.5076 ) (2013a)