Article (an2004characterizing)
An, Y.; Janssen, J. & Milios, E. E.
Characterizing and Mining the Citation Graph of the Computer Science Literature
Knowl. Inf. Syst., Springer-Verlag New York, Inc., 2004, 6, 664-678

Article (small1973cocitation)
Small, H.
Co-citation in the scientific literature: A new measure of the relationship between two documents
Journal of the American Society for Information Science, Wiley Subscription Services, Inc., A Wiley Company, 1973, 24, 265-269