Figure 3
The top of the nested hierarchy between scientific journals. Due to the rapidly increasing number of nodes per level, the journals on Levels 4 and 5 are organized into multiple rows. The size of the nodes indicates the total number of descendants (on a logarithmic scale). The journals positioned above Level 5 with no out links shown (for example, Europhysics Letters or Bioscience) have descendants on levels that are out of the scope of the figure.
