APA (7th ed.) Citation

Haichang, G., Liu, H., Yao, D., Liu, X., Aickelin, U., & Yu, F. (2010). An audio CAPTCHA to distinguish humans from computers. IEEE Computer Society.

Chicago Style (17th ed.) Citation

Haichang, Gao, Honggang Liu, Dan Yao, Xiyang Liu, Uwe Aickelin, and Fei Yu. An Audio CAPTCHA to Distinguish Humans from Computers. IEEE Computer Society, 2010.

MLA (9th ed.) Citation

Haichang, Gao, et al. An Audio CAPTCHA to Distinguish Humans from Computers. IEEE Computer Society, 2010.