Perhaps you should try some spelling variations:
obra teatral » obras teatrales
agentes per » agentes de
agentes del » agentes de, antes del, agente de
celebri de » celebri di
teatral e » teatral de, teatrales en, teatral tell
de obra » de obras
pezzi » pozzi

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "Biblioteca lirica : pezzi celebri de obra teatral e ((agentes per) OR (agentes del)) pianoforte.~".
• Adding a wildcard symbol may retrieve word variants: Biblioteca lirica : pezzi celebri de obra teatral e ((agentes per) OR (agentes del)) pianoforte.*.