MLA

Hopfe, Christina J, et al. Natural Language Processing and Information Systems. Springer Berlin Heidelberg, 2010.

APA

Hopfe, C. J, Kanade, T., Li, H., Métais, E., Preece, A., & Rezgui, Y. (2010). Natural Language Processing and Information Systems. Springer Berlin Heidelberg.

Chicago

Hopfe, Christina J., Takeo Kanade, Haijiang Li, Elisabeth Métais, Alun Preece, and Yacine Rezgui. Natural Language Processing and Information Systems. : Springer Berlin Heidelberg, 2010.