APA (7th ed.) Citation

Frey, E. (1924). Flechten ([Sonderdr.].).

Chicago Style (17th ed.) Citation

Frey, Eduard. Flechten. [Sonderdr.]. 1924.

MLA (9th ed.) Citation

Frey, Eduard. Flechten. [Sonderdr.]. 1924.

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