美國法典第3编(英语:Title 3 of the United States Code)§ 第19節 - Vacancy in offices of both President and Vice President; officers eligible to act. Legal Information Institute. Cornell University Law School.缺少或|url=为空 (帮助); 使用|accessdate=需要含有|url= (帮助)
美國法典第3编(英语:Title 3 of the United States Code)§ 第19節 - Vacancy in offices of both President and Vice President; officers eligible to act. Legal Information Institute. Cornell University Law School.缺少或|url=为空 (帮助); 使用|accessdate=需要含有|url= (帮助)