APA (7th ed.) Citation

Luther, M., & Mann, G. (1995). An Open Letter on Translating. Project Gutenberg.

Chicago Style (17th ed.) Citation

Luther, Martin, and Gary Mann. An Open Letter on Translating. Project Gutenberg, 1995.

MLA (9th ed.) Citation

Luther, Martin, and Gary Mann. An Open Letter on Translating. Project Gutenberg, 1995.

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