  With minima in the diagonal conductance G_{xx} and in the absolute value of
the derivative |dG_{xy}/dB| at the Hall conductance value G_{xy}=e^{2}/h,
spin-splitting is observed in the quantum Hall effect of heavily Si-doped GaAs
layers with low electron mobility 2000 cm^2/Vs in spite of the fact that the
spin-splitting is much smaller than the level broadening. Experimental results
can be explained in the frame of the scaling theory of the quantum Hall effect,
applied independently to each of the two spin subbands.
