Columbia subject headings:
Book industries and trade--Italy--Bologna.
Incunabula--Bibliography.
Università di Bologna.
Harvard subject headings:
Bologna (Italy)--Imprints.
Book industries and trade--Italy--Bologna.
Incunabula--Bibliography
Incunabula--Italy--Bologna--Bibliography.
Printing--Italy--Bologna--History--Origin and antecedents.
Università di Bologna
Princeton subject headings: