• [1]

    J. Schwinger, Phys. Rev, 128(1962). 2425.L S Drown, Nuovo Cimento 29(1963). 617.[2] J. Kogut and L. Susskind, Phys. Rev., D11(1975), 3594.S. Coleman, Ann. Phys.,101(1976), 239.[3] R. Roskies and F. Schaposnik, Pkys. Rev., D23(1981), 558.K. Fujikawa, Phys. Rev. Lett., 42(1979), 1195.[4] T. Banks, J. Kogut and L. Susskind, Phys. Rev, D13(1976), 1043.A. Carroll, J. Kogut, D. K. Sinclair and L. Susskind, Phys. Rev., D13(1976), 2270.[5] O. Martin and S. Otto, Nucl. Phys., B203(1982), 297.J . Bartholomew and J. Sloan, Phys. Lett,, 172B(1986), 407.