  Contrary to the general belief, there has recently been quite a few examples
of unitary evolution of quantum cosmological models. The present work gives
more examples, namely Bianchi type VI and type II. These examples are important
as they involve varying spatial curvature unlike the most talked about
homogeneous but anisotropic cosmological models like Bianchi I, V and IX. We
exhibit either explicit example of the unitary solutions of the Wheeler-DeWitt
equation, or at least show that a self-adjoint extension is possible.
