APA (7th ed.) Citation

Engels, F., & Marx, K. (2007). The Communist Manifesto. Project Gutenberg.

Chicago Style (17th ed.) Citation

Engels, Friedrich, and Karl Marx. The Communist Manifesto. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Engels, Friedrich, and Karl Marx. The Communist Manifesto. Project Gutenberg, 2007.

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