Nanjing Normal University Segmenter for the Fourth SIGHAN Bakeoff Xiaohe Chen author Bin Li author Junzhi Lu author Hongdong Nian author Xuri Tang author 2008 text Proceedings of the Sixth SIGHAN Workshop on Chinese Language Processing conference publication chen-etal-2008-nanjing https://aclanthology.org/I08-4019/ 2008