    @inproceedings {IsaacAgudo2005b,
	title = {A Representation Model of Trust Relationships with Delegation Extensions},
	booktitle = {3th International Conference on Trust Management (iTRUST{\textquoteright}05)},
	series = {LNCS},
	volume = {3477},
	year = {2005},
	month = {May},
	pages = {9-22},
	publisher = {Springer},
	organization = {Springer},
	address = {Versailles, France},
	abstract = {<p>Logic languages establish a formal framework to solve authorization and delegation conflicts. However, we consider that a visual representation is necessary since graphs are more expressive and understandable than logic languages. In this paper, and after overviewing previous works using logic languages, we present a proposal for graph representation of authorization and delegation statements. Our proposal is based on Varadharajan et al. solution, though improve several elements of that work. We also discuss about the possible implementation of our proposal using attribute certificates.</p>},
	isbn = {978-3-540-26042-4},
	issn = {0302-9743 (Print) 1611-3349 (Online)},
	doi = {10.1007/11429760_9},
	author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro}
}
