requirements: list for carriers, Government oftheUnited Kingdom, 2 October 2017. Travel without a visa, UnitedStates Department of State. 国际民用航空组织(IATA)旅行信息手冊
The European Union andtheUnitedStates: Global Partners, Global Responsibilities' (PDF). Delegation ofthe European Union totheUnitedStates. [2012-01-05]