1. Hubie Key Laboratory of Forensic Science Department of Forensic science and Intelligence Hubei University of Police No. 99 NanNiWang Road, Qiaokou District Wuhan Hubei 430035 China
2. Department of Questioned Documents The China Criminal Police University No. 83 Tawan Street Shenyang 110854 China
3. Institute of Forensic Science Ministry of Public Security No. 17, South Li Xi'an Beijing 100038 China
4. Yantai Public Security of Shan Dong province No. 7 Changan Road, Laishan District Yantai Shandong 264000 China
5. Institute of Forensic of Anhui Public Security Department No. 282 Anqing Road Hefei Anhui 230061 China