@inproceedings {AV11ECSQARU,
	author		=	"L. Amgoud and S. Vesic",
	title 		=       "Two roles of preferences in argumentation frameworks",
	booktitle 	=	"Proceedings of the 11th European Conference on Symbolic 
					and Quantitative Approaches to Reasoning with Uncertainty, (ECSQARU'11)",
	editor 		=	"W. Liu",
	publisher 	=	"Springer",
	year 		=	2011,
	pages		=	"86-97"
}