  Let $S$ be a set of vertices of a connected graph $G$. The Steiner distance
of $S$ is the minimum size of a connected subgraph of $G$ containing all the
vertices of $S$. The Steiner $k$-Wiener index is the sum of all Steiner
distances on sets of $k$ vertices of $G$. Different simple methods for
calculating the Steiner $k$-Wiener index of block graphs are presented.
