1. , and , Graphs and Digraphs, Prindle, Weber and Schmidt, Boston (1979.)
2. self-centered graphs with a given radius. In Proceedings, Tenth Southeastern Conference on Combinatorics, Graph Theory and Computing, F. Hoffman, Ed. Utilitas Math., Winnipeg (1979), pp. 211–215.
3. The central ratio of a graph
4. On graphs containing a given graph as center
5. On graphs with prescribed median II. Forthcoming.