Columbia subject headings:
Frisian language--Dialects--Germany--Sylt--Texts--Bibliography.
Schmidt, Hermann, 1901-1979--Bibliography.
Harvard subject headings:
Frisian language--Dialects--Germany--Sylt--Bibliography.
Frisian philology--Bibliography.
North Frisian dialect--Dialects--Germany--Sylt--Bibliography.
Schmidt, Hermann, 1901-1979--Bibliography.
Princeton subject headings: