Columbia subject headings:
Hats.
Headgear--Germany--History.
Harvard subject headings:
Headgear--Germany, Northern.
Low German language--To 1500--Etymology.
Low German language--To 1500--Terms and phrases.
Princeton subject headings:
Headgear--Germany, Northern.
Low German language--To 1500--Etymology.
Low German language--To 1500--Terms and phrases.