1. For general reference of critical phenomena, see “Introduction to Phase Transition and Critical Phenomena”, H.E. Stanley (Oxford University Press) 1971.
2. K.G. Wilson, Phys. Rev. B 4, 3174, 3184 (1971).
3. 3184.
4. K.G. Wilson and M.E. Fisher, Phys. Rev. Lett. 28, 240 (1972);
5. K.G. Wilson and J. Kogut, Phys. Reports 12, 75 (1974).