Marx, K. (1960). The Essential left: Four classic texts on the principles of socialism. Unwin.
Lua i Stíl Chicago (17ú heag.)Marx, Karl. The Essential Left: Four Classic Texts on the Principles of Socialism. London: Unwin, 1960.
Lua MLA (9ú heag.)Marx, Karl. The Essential Left: Four Classic Texts on the Principles of Socialism. Unwin, 1960.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.