2097
Filippeschi made several recordings , notably Pollione in Norma , opposite Maria Callas , and Carlo in Don Carlos , opposite Tito Gobbi and Boris Christoff .
 Filippeschi, Maria Callas, Tito Gobbi, Boris Christoff
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Filippeschi, Maria Callas, Tito Gobbi, Boris Christoff