APA (7th ed.) Citation

Engels, F., & Aveling, E. (2012). Socialism: Utopian and Scientific. Project Gutenberg.

Chicago Style (17th ed.) Citation

Engels, Friedrich, and Edward Aveling. Socialism: Utopian and Scientific. Project Gutenberg, 2012.

MLA (9th ed.) Citation

Engels, Friedrich, and Edward Aveling. Socialism: Utopian and Scientific. Project Gutenberg, 2012.

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