@ARTICLE {
        NBYseqidx2,
        AUTHOR = "G. Navarro and R. Baeza-Yates",
        TITLE = "A Practical $q$-Gram Index for Text Retrieval Allowing Errors",
        JOURNAL = {CLEI Electronic Journal},
        YEAR = 1998,
	VOLUME = 1,
	NUMBER = 2,
        NOTE = "{\tt http://\-www.clei.cl}."
        }