@ARTICLE {
        NPCdke07,
	TITLE = "$t$-Spanners for Metric Space Searching",
        AUTHOR = "G. Navarro and R. Paredes and E. Ch\'avez",
	JOURNAL = "Data and Knowledge Engineering",
        YEAR = 2007,
	VOLUME = 63,
	NUMBER = 3,
	PAGES = "820--854"
        }