1. J. Hartle, S.W. Hawking, Phys. Rev. D 28 (1983) 2960; R. Bousso, S.W. Hawking Lorentzian Condition in Quantum Gravity, hep-th/9807148.
2. Max Tegmark, On dimensionality of spacetime, gr-qc/9702052, or Class. Quan. Grav. 14 (1997) L69.
3. Holger Bech Nielsen and Svend E. Rugh Weyl Particles, Weak Interactions and Origin of Geometry, Nucl. Phys. B Proc. Suppl. 29 B, C (1992) 200-246; see especially p. 219 for the signature.
4. Dual Strings - Section 6. Catastrophe Theory Programme by H.B. Nielsen, in: I.M. Barbour, A.T. Davies (Eds.), Fundamentals of Quark Models, Scottish Universities Summer School in Physics (1976), pp. 528 -543; H.B. Nielsen, in: R. Raitio, J. Lindfors (Eds.), Gauge Theories of the Eighties, Springer, Berlin, 1983, p 288; H.B. Nielsen, D.L. Bennett and Niels Brene, in: J. Ambjørn, B. Duurhus, J.L. Petersen (Eds.), Recent Developments in Quantum Field Theory, Elsevier Science Publishers, 1985, p253; J. Wheeler, Law without Law, in: J.A. Wheeler, W.R. Zurek (Eds.), Quantum Theory of Measurement, Princeton University Press, 1983, p. 182; J.A. Wheeler, Beyond the Black Hole, in: H. Wolf (Ed.), Some Strangeness in Proportion, Addison-Wesley, 1980, p. 341; R.P. Feynman, The Character of Physical Law MIT Press, 1965, Penguine Books 1992; G.F. Chew, in: E. Zichichi (Ed.), Properties of Fundamental Interactions, Editrice Compositori, 1973, p. 3; C.H. Woo, Mission Impossible? A look at Past Setbacks in the Search for Elementary Matter and for Universal Symmetries, Zentrum für Interdisziplinäre Forschung, University of Bielefeld Preprint. For a recent text on Random Dynamics see: Nicolai Stillits, Cand. scient. thesis, Niels Bohr Institute, Copenhagen, 1999.
5. Holger Bech Nielsen and Svend E. Rugh, Why do we have 3+1 dimensions?, hep-th/9407011, contribution to Wendisch–Rietz meeting (Sept. 1992) B. Dörfel, W. Wieczorek (Eds.), DESY preprint 93-013, ISSN 0418-9833; S. Chadha, H.B. Nielsen, Naturalness of Weyl Equation and 3+1 Dimensionality, in A Report on Research Activities at the Niels Bohr Institute and Nordita, 1974, p. 117.