APA (7th ed.) Citation

Highsmith, P., Hopper, D., Ganz, B., Kreuzer, L., & Wenders, W. The American friend.

Chicago Style (17th ed.) Citation

Highsmith, Patricia, Dennis Hopper, Bruno Ganz, Lisa Kreuzer, and Wim Wenders. The American Friend.

MLA (9th ed.) Citation

Highsmith, Patricia, et al. The American Friend.