1. Shang-Keng, Ma: Modern theory of critical phenomena, New York: Benjamin, 1976.
2. Binney, J.J., Dowerick, H.J., Fisher, A.J., Neuman, M.E.J.: The theory of critical phenomena, Oxford: Clarendon, 1992.
3. Li, Y., Baberschke, K.: Phys. Rev. Lett. 68 (1992) 1208.
4. Bramwell, S.T., Holdsworth, P.C.W.: J. Phys.: Condens. Matter 5 (1993) L53.
5. Huang, F., Kief, M.T., Mankey, G.J., Willis, R.F.: Phys. Rev. B 49 (1994) 3962.