A. Ahadi and A. Dehghan, The complexity of the proper orientation number, Information Processing Letters, vol.113, issue.19-21, pp.19-21799, 2013.
DOI : 10.1016/j.ipl.2013.07.017

J. Araujo, N. Cohen, S. F. De-rezende, F. Havet, and P. F. Moura, On the proper orientation number of bipartite graphs, Theoretical Computer Science, vol.566, issue.0, pp.59-75, 2015.
DOI : 10.1016/j.tcs.2014.11.037

URL : https://hal.archives-ouvertes.fr/hal-01101578

J. A. Bondy and U. S. Murty, Graph theory, Graduate Texts in Mathematics, vol.244, 2008.
DOI : 10.1007/978-1-84628-970-5

P. Erd?s, Graph theory and probability. Canad, J. Math, vol.11, pp.34-38, 1959.

R. Michael, D. S. Garey, and . Johnson, Computers and Intractability: A Guide to the Theory of NP-Completeness, 1979.

A. Gyárfás, On ramsey covering-numbers, Infinite and Finite Sets, p.10, 1975.

A. Gyárfás, Problems from the world surrounding perfect graphs, Zastosow Ania Matematyki Applicationes Mathematicae XIX, pp.3-4, 1987.

D. Michael and . Plummer, Claw-free maximal planar graphs, 1989.

D. P. Sumner, Subtrees of a graph and the chromatic number, The theory and applications of graphs, pp.557-576, 1980.