1. P.C.W. Davies, J. Brown,Superstrings: A Theory of Everything? Cambridge University Press, New York, 1988, p. 1.
2. Davies, Brown,ibid, p. 67.
3. M.L. Silbar, A profound theory lurking,Mosaic, 17 (1986/87), 26.
4. M. Duff, C. Sutton, The membrane at the end of the Universe,New Scientists, 118 (1988), 67–71.
5. S. Glashow, Tangles in Superstring,The Sciences 283 (1980) 22–25.