@ARTICLE {
	AUTHOR = "Sergio Ochoa and Ricardo Valdivia and Miguel Nussbaum",
	TITLE ="Modeling a Collaborative Answer Negotiation Activity Using IMS-Based Learning Design",
	JOURNAL = "IEEE Transactions on Education (TED)",
	VOLUME = "52",
	NUMBER = "3",
	PAGES = "375-384",
	MONTH = "Jul",
	YEAR = "2009",
	PUBLISHER = "IEEE Education Society",
	ADDRESS = "Los Alamitos, CA, USA",
	ISSN = "0018-9359"
	}