MLA

Zhou, S. Kevin, et al. Unconstrained Face Recognition. Springer US, 2006.

APA

Zhou, S. Kevin, Chellappa, R., Zhao, W., Zhou, S. KZhou, S. Kevin. (2006). Unconstrained Face Recognition. Springer US.

Chicago

Zhou, S. Kevin, Rama Chellappa, Wenyi Zhao, S. K Zhou, and Shaohua Kevin Zhou. Unconstrained Face Recognition. : Springer US, 2006.