United States. National Park Service. Western Regional Office. Park and Recreation Technical Services Division. (1983). Winning support for parks and recreation. Venture.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)United States. National Park Service. Western Regional Office. Park and Recreation Technical Services Division. Winning Support for Parks and Recreation. State College, PA: Venture, 1983.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)United States. National Park Service. Western Regional Office. Park and Recreation Technical Services Division. Winning Support for Parks and Recreation. Venture, 1983.
Cảnh báo: Các trích dẫn này có thể không phải lúc nào cũng chính xác 100%.