Gregory, G. H. (2002). Alcatraz screw: My years as a guard in America's most notorious prison. University of Missouri Press.
Chicago-referens (17:e uppl.)Gregory, George H. Alcatraz Screw: My Years as a Guard in America's Most Notorious Prison. Columbia, MO: University of Missouri Press, 2002.
MLA-referens (9:e uppl.)Gregory, George H. Alcatraz Screw: My Years as a Guard in America's Most Notorious Prison. University of Missouri Press, 2002.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.