Columbia subject headings:
Boll, Ilka, 1923-1985.
Dramatists, German--Germany--Essen--Biography.
Theater--Germany--Essen--History--20th century.
Theatrical producers and directors--Germany--Essen--Biography.
Harvard subject headings:
Boll, Ilka, 1923-1985.
Dramatists--Biography.
Dramatists--Germany--Essen--Biography.
Theater--Germany--Essen--History--20th century.
Theatrical producers and directors--Germany--Essen--Biography.
Princeton subject headings:
Boll, Ilka, 1923-1985.
Dramatists--Germany Essen--Biography.
Theater--Germany--Essen--History--20th century.
Theatrical producers and directors--Germany--Essen--Biography.