Columbia subject headings:
Espionage--United States--History--20th century.
Manhattan Project (U.S.)
Spies--United States.
Harvard subject headings:
Espionage, Soviet--United States--History--20th century.
Espionage--United States--History--20th century.
Gold, Harry
Hall, Theodore, 1925-
Manhattan Project (U.S.)
Manhattan Project (U.S.)--History.
Spies--United States
Princeton subject headings:
Espionage--United States--History--20th century.
Manhattan Project (U.S.)
Spies--United States.