1. A Helly theorem in weakly modular space;Bandelt;Discrete Math.,1996
2. Modular interval spaces;Bandelt;Math. Nachr.,1993
3. Graphs and Digraphs;Chartrand,1996
4. H.M. Mulder, The Interval Function of a Graph, Math. Centre Tracts 132, Math. Centre, Amsterdam, 1980.
5. Modular and median signpost systems and their underlying graphs;Mulder;Discuss. Math. Graph Theory,2003