%A Hubert de Fraysseix %A Patrice Ossona de Mendez %J Algorithmica %T On representations by contact and intersection of segments %X 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. %N 4 %P 453-463 %V 47 %D 2007 %L gdea_3750