APA (7th ed.) Citation

Leon, T., Emma, G., & Petr, K. La libertad. Teruel: El Sembrador.

Chicago Style (17th ed.) Citation

Leon, Tolstoi, Goldman Emma, and Kropotkin Petr. La Libertad. Teruel: El Sembrador.

MLA (8th ed.) Citation

Leon, Tolstoi, et al. La Libertad. Teruel: El Sembrador.

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