Columbia subject headings:
Ecumenical movement--History.
Visser 't Hooft, Willem Adolph, 1900-1985.
Harvard subject headings:
Christian union--Europe--History.
Ecumenical movement--Europe--History.
Visser 't Hooft, Willem Adolph, 1900-1985.
Princeton subject headings:
Christian union--Europe--History.
Ecumenical movement--Europe--History.
Visser 't Hooft, Willem Adolph, 1900-1985.