  We further study the asymptotics of quantization errors for two classes of
in-homogeneous self-similar measures $\mu$. We give a new sufficient condition
for the upper quantization coefficient for $\mu$ to be finite. This, together
with our previous work, leads to a necessary and sufficient condition for the
upper and lower quantization coefficient of $\mu$ to be both positive and
finite. Furthermore, we determine (estimate) the convergence order of the
quantization error in case that the quantization coefficient is infinite.
