Columbia subject headings:
Early maps--Exhibitions.
Incunabula--Austria--Vienna--Bibliography--Exhibitions.
Incunabula--Bulgaria--Bibliography--Exhibitions.
Manuscripts, Bulgarian--Austria--Vienna--Exhibitions.
Manuscripts, Church Slavic--Exhibitions.
Manuscripts, Medieval--Austria--Vienna--Exhibitions.
Österreichische Nationalbibliothek--Exhibitions.
Harvard subject headings:
Early maps--Exhibitions.
Incunabula--Exhibitions.
Manuscripts, Bulgarian--Exhibitions.
Manuscripts, Church Slavic--Exhibitions.
Österreichische Nationalbibliothek.
Princeton subject headings:
Early maps--Exhibitions.
Incunabula--Bibliography--Exhibitions.
Manuscripts, Bulgarian--Austria--Vienna--Exhibitions.
Manuscripts, Church Slavic--Exhibitions.
Manuscripts, Medieval--Austria--Vienna--Exhibitions.
Österreichische Nationalbibliothek--Exhibitions.