APA-referens (7:e uppl.)
Howard, W. (1979). Gore Vidal's Caligula: A novel based on Gore Vidal's original screenplay. Warner books.
Chicago-referens (17:e uppl.)
Howard, William. Gore Vidal's Caligula: A Novel Based on Gore Vidal's Original Screenplay. New York: Warner books, 1979.
MLA-referens (9:e uppl.)
Howard, William. Gore Vidal's Caligula: A Novel Based on Gore Vidal's Original Screenplay. Warner books, 1979.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.