  In the paper very efficient, linear in number of arcs, algorithms for
determining Hummon and Doreian's arc weights SPLC and SPNP in citation network
are proposed, and some theoretical properties of these weights are presented.
The nonacyclicity problem in citation networks is discussed. An approach to
identify on the basis of arc weights an important small subnetwork is proposed
and illustrated on the citation networks of SOM (self organizing maps)
literature and US patents.
