Columbia subject headings:
Harvard subject headings:
Bilingualism--Italy--History--Congresses.
Italian language--Foreign elements--Spanish--Congresses.
Languages in contact--Italy--History--Congresses.
Multilingualism--Italy--History--Congresses.
Spanish language--Italy--History--Congresses.
Princeton subject headings:
Bilingualism--Italy--Congresses.
Multilingualism--Italy--Congresses.
Spaniards--Italy--Language--Congresses.