APA (7th ed.) Citation

Helmer, W. (1998). Public enemies: America's criminal past, 1919 - 1940. Facts on File.

Chicago Style (17th ed.) Citation

Helmer, William. Public Enemies: America's Criminal Past, 1919 - 1940. New York: Facts on File, 1998.

MLA (9th ed.) Citation

Helmer, William. Public Enemies: America's Criminal Past, 1919 - 1940. Facts on File, 1998.

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