Heribert Von Feilitzsch – författare

In Plain Sight: Felix A. Sommerfeld, Spymaster in Mexico, 1908 to 1914

Felix A. Sommerfeld and the Mexican Front in the Great War

The Secret War on the United States in 1915: A Tale of Sabotage, Labor Unrest, and Border Troubles

Secret War Council

The German Fight Against the Entente in America in 1914

Im Schatten der Oeffentlichkeit: Felix A. Sommerfeld, Geheimagent in Mexiko, 1908 bis 1914

The Negotiator's Toolbox: Winning Strategies for Corporate Buyers and Small Businesses

federal Bureau of Investigation before Hoover

Volume 1: The fBI and Mexican Revolutionists, 1908-1914