Perhaps you should try some spelling variations:
der pianoforte » de pianoforte, per pianoforte, del pianoforte
pozzi celebri » pezzi celebri
obra central » la central, asia central
obra teatral » obras teatrales
agentes der » agentes de, agentes del, agente de
de agentes » de fuentes

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

• Performing a fuzzy search may retrieve terms with similar spellings: Biblioteca lirica : pozzi celebri di ((obra central) OR (obra teatral)) de agentes der pianoforte.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "Biblioteca lirica : pozzi celebri di ((obra central) OR (obra teatral)) de agentes der pianoforte.*".