APA (7th ed.) Citation

Harmsen, T., Hennen, I., & Kaltenbach, M. Fighting the Hydra. University Library Heidelberg.

Chicago Style (17th ed.) Citation

Harmsen, Tjorven, Ina Hennen, and Marie Kaltenbach. Fighting the Hydra. University Library Heidelberg.

MLA (9th ed.) Citation

Harmsen, Tjorven, et al. Fighting the Hydra. University Library Heidelberg.