Columbia subject headings:
Belt, Elmer, 1893-1980--Library.
Incunabula--Bibliography--Catalogs.
Leonardo, da Vinci, 1452-1519--Sources.
Harvard subject headings:
Belt, Elmer, 1893-1980--Library.
Incunabula--Bibliography--Catalogs.
Leonardo, da Vinci, 1452-1519
Princeton subject headings: