Fig. 12From: Multiplex flows in citation networksFrom multiplex citation network (left) to layer network (right). Note that we added a layer X in orange to illustrate that external citations can be included in the co-citation relationship. In the layer network, the layer a plays obviously the most central role as it is interacting with all other layers. Note that the layer network is undirected since the relationship becomes co-occurrenceBack to article page