APA (7th ed.) Citation

United States. National Park Service. (1956). Mission 66: To provide adequate protection and development of the National park system for human use. [publisher not identified].

Chicago Style (17th ed.) Citation

United States. National Park Service. Mission 66: To Provide Adequate Protection and Development of the National Park System for Human Use. Washington: [publisher not identified], 1956.

MLA (9th ed.) Citation

United States. National Park Service. Mission 66: To Provide Adequate Protection and Development of the National Park System for Human Use. [publisher not identified], 1956.