Leiter, D.; Robertson, S. (2003). Does the principle of equivalence prevent trapped surfaces from being formed in the general relativistic collapse process?. Foundations of Physics Letters. 16 (2): 143. arXiv:astro-ph/0111421. doi:10.1023/A:1024170711427.
Mitra, A. (1998). Final state of spherical gravitational collapse and likely sources of Gamma Ray bursts. arXiv:astro-ph/9803014.
Mitra, A. (2000). Non-occurrence of trapped surfaces and black holes in spherical gravitational collapse: An abridged version. Foundations of Physics Letters. 13 (6): 543. arXiv:astro-ph/9910408. doi:10.1023/A:1007810414531.
Leiter, D.; Robertson, S. (2003). Does the principle of equivalence prevent trapped surfaces from being formed in the general relativistic collapse process?. Foundations of Physics Letters. 16 (2): 143. arXiv:astro-ph/0111421. doi:10.1023/A:1024170711427.
Mitra, A. (2000). Non-occurrence of trapped surfaces and black holes in spherical gravitational collapse: An abridged version. Foundations of Physics Letters. 13 (6): 543. arXiv:astro-ph/9910408. doi:10.1023/A:1007810414531.
Shiga, D.; «Mysterious quasar casts doubt on black holes», New Scientist: Space, 2006.[1] [Архівовано 1 травня 2015 у Wayback Machine.] (retrieved 2 December 2014)
Shiga, D.; «Mysterious quasar casts doubt on black holes», New Scientist: Space, 2006.[1] [Архівовано 1 травня 2015 у Wayback Machine.] (retrieved 2 December 2014)