Hertel, Günter, Hans-Eberhard Siebert, and Richard Vogel. “Maintaining Inter-Vehicle Spacing -Using Synergetic Effects Between Rail and Road Traffic!”. Communications - Scientific letters of the University of Zilina 1, no. 4 (December 31, 1999): 17-28. Accessed April 6, 2026. http://journals.uniza.sk/index.php/communications/article/view/103.