@ARTICLE {
        CNOis14,
	AUTHOR = "F. Claude and G. Navarro and A. Ord{\'o}{\~n}ez",
	TITLE = "The Wavelet Matrix: An Efficient Wavelet Tree for Large 
		 Alphabets",
        JOURNAL = {Information Systems},
        YEAR = 2015,
	VOLUME = 47,
	PAGES = "15--32"
        }