On the Circular Altitude of Graphs

Bamberg, J., Corr, B., Devillers, A., Hawtin, D., Pivotto, I., Swartz, E.: The circular altitude of a graph. Aust. J. Combin. 72(2), 357–368 (2018)

Cameron, P. J.: Altitude and chromatic number (2004). http://www.maths.qmul.ac.uk/~pjc/preprints/valt.pdf

Godsil, C., Royle, G.: Algebraic Graph Theory. Springer, New York (2001)

Hahn, G., Tardif, C.: Graph homomorphisms: structure and symmetry. In: G. Hahn, G. Sabidussi, (eds.), Graph Symmetry, no. 497 in NATO Adv. Sci. Inst. Ser. C Math. Phys. Sci., Kluwer, Dordrecht, pp. 107–167 (1997)

Hammack, R., Imrich, W., Klavžar, S.: Handbook of Product Graphs. Discrete Mathematics and its Applicatins, 2nd edn. CRC Press, Boca Raton, FL (2011)

Hell, P., Nešetřil, J.: Graphs and Homomorphisms. Oxford Lecture Series in Mathematics and its Applications, vol. 28. Oxford University Press, Oxford (2004)

Sabidussi, G.: Graphs with given group and given graph-theoretical properties. Can. J. Math. 9, 515–525 (1957)

Zhu, X.: Circular chromatic number: a survey. Discr. Math. 229, 371–410 (2001)