Columbia subject headings:
Musical theater--Europe--History and criticism.
Musicals--Europe--History and criticism.
Harvard subject headings:
Musical theater--Europe--History--19th century--Congresses.
Musical theater--Europe--History--20th century--Congresses.
Musicals--Europe--History and criticism--Congresses.
Princeton subject headings:
Musical theater--Europe--History and criticism.
Musicals--Europe--History and criticism.