  The EXFOR database contains the largest collection of experimental nuclear
reaction data available as well as the data's bibliographic information and
experimental details. We created an undirected graph from the EXFOR datasets
with graph nodes representing single observables and graph links representing
the various types of connections between these observables. This graph is an
abstract representation of the connections in EXFOR, similar to graphs of
social networks, authorship networks, etc. By analyzing this abstract graph, we
are able to address very specific questions such as 1) what observables are
being used as reference measurements by the experimental nuclear science
community? 2) are these observables given the attention needed by various
nuclear data evaluation projects? 3) are there classes of observables that are
not connected to these reference measurements? In addressing these questions,
we propose several (mostly cross section) observables that should be evaluated
and made into reaction reference standards.
