APA (7th ed.) Citation

Humboldt, W. v., Flitner, A., & Giel, K. Werke. J. G. Cotta'sche Buchhandlung.

Chicago Style (17th ed.) Citation

Humboldt, Wilhelm von, Andreas Flitner, and Klaus Giel. Werke. Stuttgart: J. G. Cotta'sche Buchhandlung.

MLA (8th ed.) Citation

Humboldt, Wilhelm von, et al. Werke. J. G. Cotta'sche Buchhandlung.