Effective dimension of quasiparticle states and remnant Fermi surface in   oxychlorides Ca_2CuO_2Cl_2 and Sr_2CuO_2Cl_2
  Formal similarity between k- area for the contribution from ZR-states and the remnant Fermi surface has been found. Presence of the contribution from 3B_{1g}- states at other k- area means the two-channel processes of scattering. As consequence, the method of integration with a constant energy interval reproduces not only remnant Fermi surface at least, but one of the contributions of above states to the total spectral intensity 
V.A.Gavrichkov