Josep Llados, Enric Marti, & Jaime Lopez-Krahe. (1999).<a target='_blank' href='/files/LIM1999b.pdf'> "A Hough-based method for hatched pattern detection in maps and diagrams "</a> In _Proceeding of the Fifth Int. Conf. Document Analysis and Recognition ICDAR ’99_ (pp. 479&ndash;482).