APA

United States, . (2016). Modernizing the National Park Service concession program: hearing before the Subcommittee on the Interior of the Committee on Oversight and Government Reform, House of Representatives, One Hundred Fourteenth Congress, first session, July 23, 2015. Washington: U.S. Government Publishing Office.

Chicago

United States, . 2016. Modernizing the National Park Service concession program: hearing before the Subcommittee on the Interior of the Committee on Oversight and Government Reform, House of Representatives, One Hundred Fourteenth Congress, first session, July 23, 2015. Washington: U.S. Government Publishing Office.

Harvard

United States, . (2016). Modernizing the National Park Service concession program: hearing before the Subcommittee on the Interior of the Committee on Oversight and Government Reform, House of Representatives, One Hundred Fourteenth Congress, first session, July 23, 2015. Washington: U.S. Government Publishing Office.

MLA

United States, . Modernizing the National Park Service concession program: hearing before the Subcommittee on the Interior of the Committee on Oversight and Government Reform, House of Representatives, One Hundred Fourteenth Congress, first session, July 23, 2015. Washington: U.S. Government Publishing Office. 2016.