The Emperor's New Mind, R. Penrose, 1989. Oxford: Oxford University Press. 1.6, 1.8, 1.11, 1.12, 1.13, 1.16(a), (b) and (c), 1.18, 1.19, 1.24, 1.25, 1.26, 1.28(a) and (b), 1.29, 1.30, 2.2, 2.5(a), 3.20.
Shadows of the Mind, R. Penrose, 1994. Oxford: Oxford University Press. 1.14, 2.3, 2.4, 2.5(b), 2.6, 2.7, 2.19, 2.20, 3.7, 3.8, 3.10, 3.11, 3.12,3.13,3.14,3.16,3.17,3.18.
High Energy Astrophysics, Volume 2, M. S. Longair, 1994. Cambridge: Cambridge University Press. 1.15, 1.22.
С разрешения Cordon Art-Baarn-Holand © 1989. 1.17, 1.19.