Columbia subject headings:
Harvard subject headings:
Educational change--Europe--History--20th century--Congresses.
Educational change--Germany--History--20th century--Congresses.
Germany--History--Unification, 1990--Congresses.
Teaching--Germany--Aids and devices--History--20th century--Congresses.
Textbooks--Europe--Congresses.
Textbooks--Germany--Congresses.
Textbooks--State supervision--Germany--Congresses.
Princeton subject headings:
Educational change--Europe--History--20th century--Congresses.
Educational change--Germany--History--20th century--Congresses.
Germany--History--Unification, 1990--Congresses.
Teaching--Germany--Aids and devices--History--20th century--Congresses.
Textbooks--Europe--Congresses.
Textbooks--Germany--Congresses.
Textbooks--State supervision--Germany--Congresses.