Columbia subject headings:
Early printed books--16th century--Union lists.
Portugal--Imprints--Union lists.
Printing--Portugal--History.
Printing--Spain--History.
Spain--Imprints--Union lists.
Harvard subject headings:
Early printed books--16th century--Union lists.
Portugal--Imprints--Union lists.
Printing--Portugal--History.
Printing--Spain--History
Spain--Imprints--Union lists.
Princeton subject headings:
Bibliography--Portugal--Early printed books--16th century--Union lists.
Bibliography--Spain--Early printed books--16th century--Union lists.
Portugal--Imprints--Union lists.
Printing--Portugal--History--16th century.
Printing--Spain--History--16th century.
Spain--Imprints--Union lists.
Union catalogs.