Columbia subject headings:
Incunabula.
Printers' marks, German.
Printing--Germany--History.
Harvard subject headings:
Germany--Imprints.
Incunabula--Germany--Bibliography.
Incunabula--Germany.
Printers' marks--Germany.
Printing--Germany--History--Origin and antecedents.
Printing--Germany--History.
Princeton subject headings:
Incunabula.
Printers' marks--Germany--History--15th century.
Printing--Germany--History.