Columbia subject headings:
Missing in action.
Prisoners of war--United States.
United States--Foreign relations--Vietnam.
Vietnam War, 1961-1975--Missing in action.
Vietnam War, 1961-1975--Prisoners and prisons, American.
Vietnam--Foreign relations--United States.
Harvard subject headings:
United States--Foreign relations--Vietnam.
Vietnam War, 1961-1975--Missing in action
Vietnam War, 1961-1975--Prisoners and prisons, American
Vietnam--Foreign relations--United States.
Princeton subject headings:
United States--Foreign relations--Vietnam.
Vietnam War, 1961-1975--Missing in action.
Vietnam War, 1961-1975--Prisoners and prisons, American.
Vietnam--Foreign relations--United States.