Uniform emulations are a method to obtain efficient and structure-preserving simulations of large networks on smaller networks. We show that for every fixed graph H, which is connected (or strongly connected in the case of directed graphs) but not complete, the problem to decide whether another (strongly) connected graph G can be uniformly emulated on H is NP-complete. © 1988.
Bodlaender, H. L. (1988). The complexity of finding uniform emulations on fixed graphs. Information Processing Letters, 29(3), 137–141. https://doi.org/10.1016/0020-0190(88)90051-8