| [1] | Z. Shou-Hua, Chin. Phys. Lett., 24 (2): 381 (2007) | 
	
			| [2] | S. C. Yoon, F. Iocco, S. Akiyama, Astrophys. J, 688: L1 (2008) | 
	
			| [3] | Y. Hosotani, P. Ko, M. Tanaka, Phys. Lett. B, 680: 179 (2009) | 
	
			| [4] | Andrzej M. Szelc, Acta Phys. Polon. B, 41: 1417 (2010) | 
	
			| [5] | J. Goodman et al, Nucl. Phys. B, 844: 55 (2011) | 
	
			| [6] | Q. Hong-Yi, W. Wen-Yu, X. Zhao-Hua, Chin. Phys. Lett., 28: 111202 (2011) | 
	
			| [7] | Q. Hong-Yi, W. Wen-Yu, X. Zhao-Hua (CMS Collaboration), JHEP, 09: 094 (2012) | 
	
			| [8] | L. Xu, Y. Chang, Phys. Rev. D, 88: 127301 (2013) | 
	
			| [9] | A. Crivellin, F. D'Eramo, M. Procura, Phys. Rev. Lett., 112: 191304 (2014) | 
	
			| [10] | L. Carpenter et al, Phys. Rev. D, 89: 075017 (2014) | 
	
			| [11] | K. Freese, arXiv:1501.02394, invited review for Reports on Progress in Physics | 
	
			| [12] | J. March-Russell, S. M. West, D. Cumberbatch, and D. Hooper, JHEP, 7: 058 (2008) | 
	
			| [13] | C. Englert, T. Plehn, D. Zerwas, and P. M. Zerwas, Phys. Lett. B, 703: 298 (2011) | 
	
			| [14] | L. Lopez-Honorez, T. Schwetza, J. Zupan, Phys. Lett. B, 716: 179 (2012) | 
	
			| [15] | W. Krlikowski, arXiv: 1008. 4756 | 
	
			| [16] | W. Krlikowski, Acta Phys. Polon. B, 39: 1881 (2008) | 
	
			| [17] | W. Krlikowski, Acta. Phys. Polon. B, 40: 111 (2009) | 
	
			| [18] | W. Krlikowski, Acta . Phys. Polon. B, 40: 2767 (2009) | 
	
			| [19] | W. Krlikowski, Acta. Phys. Polon. B, 42: 1261 (2011) | 
	
			| [20] | Y. Nomura, J. Thaler, Phys. Rev. D, 79: 075008 (2009) | 
	
			| [21] | J. Cherry, A. Friedland, I. M. Shoemaker, arXiv: 1411.1071 | 
	
			| [22] | Jiang-Hao Yu, Phys. Rev. D, 90: 095010 (2014) | 
	
			| [23] | M. Hamzavi et al, Chin. Phys. Lett., 21: 80302 (2012) | 
	
			| [24] | L. Essen et al, Nature, 229 (1971) | 
	
			| [25] | D. McKeen, Annals Phys., 326: 1501 (2011) | 
	
			| [26] | J. P. Miller, E. de Rafael, and B. Lee Roberts, Rept. Prog. Phys., 70: 795 (2007) | 
	
			| [27] | W. Krlikowski, arXiv: 0903.5163 | 
	
			| [28] | K. Olive et al, Review of Particle Physics, Chin. Phys. C, 38: 090001 (2014) | 
	
			| [29] | P. deNiverville, D. McKeen, A. Ritz, Phys. Rev. D, 86: 035022 (2012) | 
	
			| [30] | P. deNiverville, M. Pospelov, A. Ritz, Phys. Rev. D, 84, 075020 (2011) | 
	
			| [31] | B. Batell, R. Essig, Z. Surujon, Phys. Rev. Lett. 113: 171802 (2014) | 
	
			| [32] | B. Batell, M. Pospelov, and A. Ritz, Phys. Rev. D, 80: 095024 (2009) | 
	
			| [33] | R. Essig et al, JHEP, 11: 167 (2013) | 
	
			| [34] | K. N. Abazajian, Physics, 7: 128 (2014) | 
	
			| [35] | A. Merle, A. Schneider, Report number: MPP-2014-348, arXiv:1409.6311 | 
	
			| [36] | Babette Dbrich, arXiv:1501.03274, Report number: DESY 15-003, contribution to the 24th European Cosmic Ray Symposium. | 
	
			| [37] | P. Masjuan, Nuclear Physics B, Proceedings Supplement 00: 1 (2014) | 
	
			| [38] | G. Eichman et al, arXiv: 1411.7876 | 
	
			| [39] | S. Henry (University of Oxford), News From Fermilab, https: //indico.in2p3.fr/event/10304/contribution/20/material/ slides/. December 9, 2014 | 
	
			| [40] | M. R. Francis, Symmetry, A joint Fermilab/SLAC publication, January 2015 | 
	
			| [41] | E. Bulbul et al, Astrophys, J, 789: 13 (2014) | 
	
			| [42] | A. Boyarsky et al, Phys. Rev. Lett., 113: 251301 (2014) | 
	
			| [43] | Javier Redondo, MPP-2014-33, arXiv:1501.07292 | 
	
			| [44] | A. Mirizzi, J. Redondo, and G. Sigl, JCAP, 0903: 026 (2009) | 
	
			| [45] | A. P. Lobanov, H. -S. Zechlin, and D. Horns, Phys. Rev. D, 87: 6065004 (2013) | 
	
			| [46] | J. Redondo, A. Ringwald, Contemp. Phys., 52: 211 (2011) | 
	
			| [47] | H. Vogel, J. Redondo, JCAP, 1402: 029 (2014) | 
	
			| [48] | J. Redondo, M. Postma, JCAP, 0902: 005 (2009) |