Hospers, J. (1971). Libertarianism, A political philosophy for tomorrow (Primera edición.). Reason Press.
Lua i Stíl Chicago (17ú heag.)Hospers, John. Libertarianism, A Political Philosophy for Tomorrow. Primera edición. Santa Bárbara: Reason Press, 1971.
Lua MLA (8ú heag.)Hospers, John. Libertarianism, A Political Philosophy for Tomorrow. Primera edición. Reason Press, 1971.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.