Haichang, G., Liu, H., Yao, D., Liu, X., & Aickelin, U. (2010). An audio CAPTCHA to distinguish humans from computers. In F. Yu, M. Russell, N. Rubens, & J. Zhang (Eds.), Third International Symposium on Electronic Commerce and Security, ISECS2010: Guangzhou, China, 29-31 July 2010. IEEE Computer Society