Columbia subject headings:
Harvard subject headings:
Birth control--History--20th century--Congresses.
Contraception--History--20th century--Congresses.
Family planning--History--20th century--Congresses.
Fertility, Human--History--20th century--Congresses.
Princeton subject headings:
Birth control--20th century--History--Congresses.
Contraception--20th century--History--Congresses.
Family planning--20th century--History--Congresses.
Fertility, Human--20th century--History--Congresses.