Investigating the topology of interacting networks - Theory and application to coupled climate subnetworksJ.F. Donges, H.C.H. Schultz, N. Marwan, Y. Zou and J. KurthsEur. Phys. J. B, 84 4 (2011) 635-651DOI: https://doi.org/10.1140/epjb/e2011-10795-8