A Survey on Breaking Technique of Text-Based CAPTCHA. - Jun Chen 011; Xiangyang Luo; Yanqing Guo; Yi Zhang 026; Daofu Gong (Secur. Commun. Networks, 2017)

Selective Learning Confusion Class for Text-Based CAPTCHA Recognition. - Jun Chen 011; Xiangyang Luo; Yingying Liu; Jinwei Wang; Yuanyuan Ma (IEEE Access, 2019)