APA (7th ed.) Citation

Ostwald, W., & Lenz, A. E. (2011). Ernst Haeckel Historische Reihe freigeistiger Texte.

Chicago Style (17th ed.) Citation

Ostwald, Wilhelm, and Arnher E. Lenz. "Ernst Haeckel." Historische Reihe Freigeistiger Texte 2011.

MLA (8th ed.) Citation

Ostwald, Wilhelm, and Arnher E. Lenz. "Ernst Haeckel." Historische Reihe Freigeistiger Texte, 2011.

Warning: These citations may not always be 100% accurate.