Columbia subject headings:
Harvard subject headings:
Carl Zeiss (Firm : 1846)--History.
Carl Zeiss (Firm : 1946)--History.
Periscopes--Germany--History.
Princeton subject headings:
Carl Zeiss (Firm : 1846)--History.
Carl Zeiss (Firm : 1946)--History.
Periscopes--Germany--History.