Steen, M. (2014). Verdi's Il Trovatore: A short guide to a great opera. Original Writing.
Chicago-viite (17. p.)Steen, Michael. Verdi's Il Trovatore: A Short Guide to a Great Opera. Dublin, Ireland: Original Writing, 2014.
MLA-viite (9. p.)Steen, Michael. Verdi's Il Trovatore: A Short Guide to a Great Opera. Original Writing, 2014.
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