http://gdea.informatik.uni-koeln.de/750/ On representations by contact and intersection of segments A necessary and sufficient condition is given for a connected bipartite graph to be the incidence graph of a contact family of segments and points. We deduce that any 4-connected 3-colorable plane graph is the contact graph of a family of segments and that any 4-colored planar graph without an induced C4 using 4 colors is the intersection graph of a family of straight line segments. de Fraysseix, Hubert Ossona de Mendez, Patrice Z.500 M.999 P.999 Z.250 On representations by contact and intersection of segments 2007-03-27 de Fraysseix, Hubert and Ossona de Mendez, Patrice (2007) On representations by contact and intersection of segments. [Journal (Paginated)]