Columbia subject headings:
World War, 1914-1918--Mexico--Fiction.
World War, 1914-1918--Secret service--Fiction.
Harvard subject headings:
Carranza, Venustiano, 1859-1920--Fiction.
Mexico--History--1910-1946--Fiction.
Wilson, Woodrow, 1856-1924--Fiction.
World War, 1914-1918--Mexico--Fiction.
World War, 1914-1918--Secret service--Fiction.
Zimmermann, Arthur, 1864-1940--Fiction.
Princeton subject headings:
Fiction.
Mexico--History--1910-1946--Fiction.
World War, 1914-1918--Fiction.