Smarandache Multi-Space Theory(II)--Multi-spaces on graphs
  A Smarandache multi-space is a union of $n$ different spaces equipped with some different structures for an integer $n\geq 2$, which can be both used for discrete or connected spaces, particularly for geometries and spacetimes in theoretical physics. This is second part on multi-spaces. Many conceptions in graphs are generalized by Smarandache's notion, such as multi-voltage graphs, Cayley graphs of a finite multi-group,multi-embedding of a graph in an $n$-manifold, graph phase, $...$, etc.. New results are obtained. 
Linfan Mao