1. L. Euler (1736) Solutio problematis ad geometriam situs pertinentis, Commentarii Accademiae Scientiarum Imperialis Pietropolitanae 8, 128–140
2. J. Nocedal, S.J. Wright (2002) Numerical Optimization, Springer, New York
3. N.L. Biggs, E.K. Lloyd, R.J. Wilson (1976) Graph Theory 1736–1936, Claredon Press, Oxford
4. http://en.wikipedia.org/wiki/Seven_Bridges_of_Königsberg
5. http://en.wikipedia.org/wiki/Edsger_W._Dijkstra