Item from Mathematical Reviews (American Mathematical Society)--access
their stable url through the AMS database via an institutional library:
MR1244291 (94j:05132) Everett, Martin G.; Borgatti, Stephen P. An
extension of regular colouring of graphs to digraphs, networks and
hypergraphs. Social Networks 15 (1993), no. 3, 237--254. (Reviewer:
Sandra L. Arlinghaus) 05C90 (05C15 05C20 05C65)