@article{DMGT_2003_23_2_a7,
     author = {Mulder, Henry and Nebesk\'y, Ladislav},
     title = {Modular and median signpost systems and their underlying graphs},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {309--324},
     publisher = {mathdoc},
     volume = {23},
     number = {2},
     year = {2003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2003_23_2_a7/}
}