@article {MR2488550,
	title = {Congruences on monoids of transformations preserving the orientation of a finite chain},
	journal = {J. Algebra},
	volume = {321},
	number = {3},
	year = {2009},
	pages = {743{\textendash}757},
	issn = {0021-8693},
	doi = {10.1016/j.jalgebra.2008.11.005},
	url = {http://dx.doi.org/10.1016/j.jalgebra.2008.11.005},
	author = {Fernandes, V{\'\i}tor H. and Gomes, Gracinda M. S. and Jesus, Manuel M.}
}
