APA (7th ed.) Citation

Engel-Hardt, R. (1959). Wunder der Natur. Rudolf Arnold Verlag.

Chicago Style (17th ed.) Citation

Engel-Hardt, Rudolf. Wunder Der Natur. Leipzig: Rudolf Arnold Verlag, 1959.

MLA (8th ed.) Citation

Engel-Hardt, Rudolf. Wunder Der Natur. Rudolf Arnold Verlag, 1959.

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