APA (7th ed.) Citation

Mackintosh, B. (1989). The United States Park Police. History Div., National Park Service, Dep. of the Interior.

Chicago Style (17th ed.) Citation

Mackintosh, Barry. The United States Park Police. Washington, DC: History Div., National Park Service, Dep. of the Interior, 1989.

MLA (9th ed.) Citation

Mackintosh, Barry. The United States Park Police. History Div., National Park Service, Dep. of the Interior, 1989.

Warning: These citations may not always be 100% accurate.