Research front maps are diagrammatic representations of the core papers
comprising each front. They are selected from the current Research Front
set that are relevant to the featured special topic.
Each circle represents a highly cited paper whose bibliographic information
is displayed when the user clicks on the circle. The solid lines between
circles represent the strongest co-citation links for each paper (that is,
indicating that the papers are frequently cited together); weaker links are
indicated by dashed lines. Papers close to each other on the map are
generally more highly co-cited. The most recent paper(s) are indicated in
pink.