The study of the network of networks, or interdependent networks, has become increasingly important. Interdependent networks are hugely prevalent especially in food, water, and fuel delivery systems. Scientists at Northeastern, Beihang, and Bar-Ilan Universities wrote in the National Science Review that the study of network of networks is “one of the most important directions in network science”.
Read more here: http://phys.org/news/2014-12-
