APA (7th ed.) Citation

Marx, K., & Engels, F. (1972). Briefe über "Das Kapital".

Chicago Style (17th ed.) Citation

Marx, Karl, and Friedrich Engels. Briefe über "Das Kapital". 1972.

MLA (8th ed.) Citation

Marx, Karl, and Friedrich Engels. Briefe über "Das Kapital". 1972.

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