アメリカ合衆国製版印刷局
↑ Treasury.gov Archived December 26, 2007, at the Wayback Machine.
↑ Dempsey, John S.; Forst, Linda S. (2009). An Introduction to Policing. Cengage Learning. p. 63. ISBN 978-1435480537. https://books.google.com/books?id=uajZhTYdmVsC&pg=PA63