Wallis, R. (2003). How safe are our skies?: Assessing the airlines' response to terrorism. Praeger.
Chicago-referens (17:e uppl.)Wallis, Rodney. How Safe Are Our Skies?: Assessing the Airlines' Response to Terrorism. Westport, Conn.: Praeger, 2003.
MLA-referens (9:e uppl.)Wallis, Rodney. How Safe Are Our Skies?: Assessing the Airlines' Response to Terrorism. Praeger, 2003.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.