On the theory of pseudogap anisotropy in the cuprate superconductors
  We show by means of the theory of the order parameter phase fluctuations that the temperature of "closing" (or "opening") of the gap (and pseudogap) in the electron spectra of superconductors with anisotropic order parameter takes place within a finite temperature range. Every Fourier-component of the order parameter has its own critical temperature. 
V.M.Loktev, V.Turkowski