Columbia subject headings:
Homosexuality--Congresses.
Lesbianism--Congresses.
Harvard subject headings:
Homosexuality
Homosexuality--Congresses.
Homosexuality--Social aspects--Congresses.
Lesbianism--Congresses.
Lesbianism--Social aspects--Congresses.
Princeton subject headings:
Homosexuality--Congresses.
Lesbianism--Congresses.