Columbia subject headings:
Cologne (Germany)--Church history--18th century.
Cologne (Germany)--Church history--19th century.
Protestants--Germany--Cologne--History--18th century.
Protestants--Germany--Cologne--History--19th century.
Harvard subject headings:
Cologne (Germany)--Church history.
Protestants--Germany--Cologne--History--18th century.
Protestants--Germany--Cologne--History--19th century.
Princeton subject headings:
Protestants--Germany (West)--Cologne--History--18th century.
Protestants--Germany (West)--Cologne--History--19th century.