Book: Runciman, Steven. A History of the Crusades: Volume 3, The Kingdom of Acre and the Later Crusades. Cambridge University Press. 1987. 9780521347723.
Web site: How many U.S. Ambassadors have been killed by militants? . Office of the Historian, Bureau of Public Affairs United States Department of State . 2017-04-22 . 2019-07-12 . https://web.archive.org/web/20190712150518/https://history.state.gov/about/faq/ambassadors-killed . dead .