APA (7th ed.) Citation

Bungert, H., Heitmann, J., & Wala, M. (2003). Secret intelligence in the twentieth century. Frank Cass.

Chicago Style (17th ed.) Citation

Bungert, Heike, Jan Heitmann, and Michael Wala. Secret Intelligence in the Twentieth Century. London ; Portland, Or.: Frank Cass, 2003.

MLA (9th ed.) Citation

Bungert, Heike, et al. Secret Intelligence in the Twentieth Century. Frank Cass, 2003.