APA (7th ed.) Citation

Labriola, A., & Kerr, C. H. (2010). Essays on the Materialistic Conception of History. Project Gutenberg.

Chicago Style (17th ed.) Citation

Labriola, Antonio, and Charles H. Kerr. Essays on the Materialistic Conception of History. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Labriola, Antonio, and Charles H. Kerr. Essays on the Materialistic Conception of History. Project Gutenberg, 2010.

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