  The observation of the characteristic Kosterlitz-Thouless behavior requires
the attaintment of the two dimensional limit where the correlation-length
anisotropy, gamma=gsiab/gsic, diverges. Our findings strongly suggest that the
failure of several experiments on films and single crystals to observe any
trace of KT-behavior is attributable either to inhomogeneities or doping by
means of chemical substitution.
