Columbia subject headings:
Frankfurter Oper.
Gielen, Michael, 1927-2019.
Opera--Germany--Frankfurt am Main.
Harvard subject headings:
Frankfurter Oper.
Gielen, Michael, 1927-2019
Opera--Germany--Frankfurt am Main.
Princeton subject headings:
Frankfurter Oper.
Gielen, Michael, 1927-
Opera--Germany (West)--Frankfurt am Main.