Columbia subject headings:
Ballads, Catalan--Bibliography--Union lists.
Ballads, Portuguese--Bibliography--Union lists.
Ballads, Spanish--Bibliography--Union lists.
Union catalogs.
Harvard subject headings:
Ballads, Catalan--Bibliography--Union lists.
Ballads, Portuguese--Bibliography--Union lists.
Ballads, Spanish--Bibliography--Union lists.
Union catalogs.
Princeton subject headings:
Ballads, Catalan--Bibliography--Union lists.
Ballads, Portuguese--Bibliography--Union lists.
Ballads, Spanish--Bibliography--Union lists.
Union catalogs.