The role of core documents in bibliometric network analysis and their relation with h-type indices

The notion of core documents and their application is discussed in the context of scientometric networks. An interesting solution of the problem of the arbitrariness of thresholds emerges from the application of Hirsch-type indices to dense networks as are typically observed in local clustering. Examples from several disciplines in the sciences and social sciences illustrate how these core vertices can be determined using this approach, and visualise how core documents are applied to represent the internal structure of the complete network or of parts of it.