@conference {383,
	title = {Definability for Downward and Vertical XPath on Data Trees},
	booktitle = {Logic, Language, Information, and Computation - 21st International Workshop, WoLLIC 2014, Valpara{\'{\i}}so, Chile, September 1-4, 2014. Proceedings},
	year = {2014},
	doi = {10.1007/978-3-662-44145-9_2},
	url = {http://dx.doi.org/10.1007/978-3-662-44145-9_2},
	author = {Sergio Abriola and Mar{\'\i}a Emilia Descotte and Santiago Figueira}
}