Gonzalo Navarro Erkki Sutinen Jorma Tarhio Indexing text with approximate <i>q</i>-grams. 157-175 2005 3 J. Discrete Algorithms 2-4 http://dx.doi.org/10.1016/j.jda.2004.08.003 db/journals/jda/jda3.html#NavarroST05