[1] E.L. Lawler et al., "The Travelling Salesman Problem", John Wiley & Sons, 1985
[2] D.P. Bertsekas, "Dynamic Programming", Prentice Hall, 1987
[3] P. Läuchli, "Algorithmische Graphentheorie", Birkhäuser, Basel, 1991
[4] Th. Riedel, "Reglerentwurf für Verkehrskreuzungen, theoretische Aspekte (Some Theoretical Aspects for Designing Traffic Light Controllers)", Report No. 91-19, ETH Zürich, 1991 (also presented with title "A Generic DEDS Control" at: Workshop on Discrete Event Systems, Amherst MA, June 1991