@ARTICLE {
        NBYtois97,
        TITLE = "Proximal {N}odes: a model to query document databases by content and structure",
        AUTHOR = "G. Navarro and R. Baeza-Yates",
        JOURNAL = {ACM Transactions on Information Systems (TOIS)},
        YEAR = 1997,
	VOLUME = 15,
	NUMBER = 4,
	PAGES = "400--435"
        }