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2. S. W. Hawking, The Universe in a Nutshell (New York: Bantam books, 2001).
3. T. Regge, Cronache Dell’ Universo (P. Boringhieri, Torino, 1981).
4. A. A. Grib and Yu. V. Pavlov, Is it possible to see the infinite future of the Universe when falling onto a black hole?, Phys.Usp. 52(3) 257–261 (2009).
5. A. A. Grib and A. M. Rasulova, Can one see the infinite future of the Universe when falling to Kerr and Reissner-Nordstrom black holes?, Grav. Cosmol. 18(3), 168–174 (2012).