APA

United States, . (2019). Event horizon telescope: the black hole seen round the world : hearing before the Committee on Science, Space, and Technology, House of Representatives, One Hundred Sixteenth Congress, first session, June 12, 2019. Washington: U.S. Government Publishing Office.

Chicago

United States, . 2019. Event horizon telescope: the black hole seen round the world : hearing before the Committee on Science, Space, and Technology, House of Representatives, One Hundred Sixteenth Congress, first session, June 12, 2019. Washington: U.S. Government Publishing Office.

Harvard

United States, . (2019). Event horizon telescope: the black hole seen round the world : hearing before the Committee on Science, Space, and Technology, House of Representatives, One Hundred Sixteenth Congress, first session, June 12, 2019. Washington: U.S. Government Publishing Office.

MLA

United States, . Event horizon telescope: the black hole seen round the world : hearing before the Committee on Science, Space, and Technology, House of Representatives, One Hundred Sixteenth Congress, first session, June 12, 2019. Washington: U.S. Government Publishing Office. 2019.