1. Archdeacon, D.: Coupled coloring of planar maps. Congr. Numer. 39, 89–94 (1986)
2. Behzad, M.: Graphs and their chromatic numbers, Ph.D. Thesis, Michigan State University (1965)
3. Behzad, M., Chartrand, G.: An Introduction to total graphs. In: Rosenstiehl, P. (ed.) Theory of Graphs. International Symposium, Rome, July 1966, pp. 31–33. Gordon and Breach, New York (1967)
4. Behzad, M., Chartrand, G., Lesniak-Foster, L.: Graphs & Digraphs. Prindle, Weber & Schmidt, Boston (1979)
5. Borodin, O.V.: Colorings of plane graphs: a survey. Discret. Math. 313(4), 517–539 (2013)