Columbia subject headings:
Harvard subject headings:
German language--Orthography and spelling--History.
German language--Orthography and spelling--Study and teaching (Elementary)
German language--Orthography and spelling--Study and teaching (Secondary)
Princeton subject headings:
German language--Orthography and spelling--History.
German language--Orthography and spelling--Study and teaching (Elementary)
German language--Orthography and spelling--Study and teaching (Secondary)