APA (7th ed.) Citation

Hammann, P., & Erichson, B. (1978). Marktforschung. Fischer.

Chicago Style (17th ed.) Citation

Hammann, Peter, and Bernd Erichson. Marktforschung. Stuttgart: Fischer, 1978.

MLA (9th ed.) Citation

Hammann, Peter, and Bernd Erichson. Marktforschung. Fischer, 1978.