Carla Binucci, Emilio Di Giacomo, Walter Didimo, Alejandro Estrella-Balderrama, Fabrizio Frati, Stephen G. Kobourov, Giuseppe Liotta. On Directed Graphs with an Upward Straight-line. In Proceedings of the 21st Annual Canadian Conference on Computational Geometry, Vancouver, British Columbia, Canada, August 17-19, 2009. pages 21-24, 2009. [doi]
Abstract is missing.