Columbia subject headings:
Harvard subject headings:
Blind--Germany--History--20th century--Congresses.
Germany--Social conditions--1933-1945--Congresses.
National socialism--Moral and ethical aspects--Congresses.
Princeton subject headings:
Blind--Germany--History--20th century--Congresses.
Blindness--Germany--Congresses.
Eugenics--Germany--History--20th century.
Eugenics--Government policy--Germany--History--20th century.