  This paper is a continuation of the paper Int. Electron. J. Algebra 6 (2009),
219-227. Namely, we introduce and study a doubly filtered set of classes of
rings of finite Gorenstein global dimension, which are called $(n,m)$-SG for
integers $n\geq 1$ and $m\geq 0$. Examples of $(n,m)$-SG rings, for $n=1$ and 2
and every $m\geq 0$, are given.
