Snooks, G. D. (1998). The laws of history. Routledge.
Lua i Stíl Chicago (17ú heag.)Snooks, G. D. The Laws of History. London ; New York: Routledge, 1998.
Lua MLA (9ú heag.)Snooks, G. D. The Laws of History. Routledge, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.