1. M.E.J. Newman, A.L. Barabasi, D.J. Watts, The structure and dynamics of networks (Princeton University Press, Princeton, NJ, 2006)
2. T.S. Evans, R. Lambiotte, Phys. Rev. E 80, 016105 (2009)
3. H. Whitney, Am. J. Math. 54, 150 (1932)
4. F. Harary, R.Z. Norman, Rendiconti del Circulo Mathematico di Palermo 9, 161 (1960)
5. R.L. Hemminger, L.W. Beineke, Line Graphs and Line Digraphs in Selected Topics in Graph Theory, edited by L.W. Beineke, R.J. Wilson (Academic Press Inc., 1978)