Ardrey, R. (1970). The social contract: A personal enquiry into the evolutionary sources of order and disorder. Collins.
Lua i Stíl Chicago (17ú heag.)Ardrey, Robert. The Social Contract: A Personal Enquiry into the Evolutionary Sources of Order and Disorder. London: Collins, 1970.
Lua MLA (9ú heag.)Ardrey, Robert. The Social Contract: A Personal Enquiry into the Evolutionary Sources of Order and Disorder. Collins, 1970.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.