Belgorod State University "The end of capitalpunishmentinEurope" Archive.is的存檔,存档日期2012-08-02, CapitalPunishment UK "Death Penalty Statistics 2006" (页面存档备份,存于互联网档案馆)
2016-09-20 [2020-04-17]. (原始内容存档于2021-05-12). The end of capitalpunishmentinEurope. CapitalPunishment U.K. [2011-04-30]. (原始内容存档于2012-08-02). June 13th
6%的葡萄牙受访者认为死刑永远都是不合理的,只有1.5%的人认为死刑总是合理的。 "The end of capitalpunishmentinEurope" Archive.is的存檔,存档日期2012-08-02, CapitalPunishment UK Law 635: Amendment to the Portuguese