Columbia subject headings:
Espionage--Ukraine--History--20th century.
Intelligence officers--Ukraine--Biography.
Secret service--Ukraine--History--20th century.
Ukraine--History--1921-1944.
Ukraine--History--Revolution, 1917-1921.
Harvard subject headings:
Secret service--Ukraine--Biography.
Secret service--Ukraine--History--20th century.
Princeton subject headings:
Secret service--Ukraine--Biography.
Secret service--Ukraine--History--20th century.