Assertion: libretto | /r/HasProperty | based on book
Facets:
value: by another writer
type: OTHER
value: very often
type: DEGREE
Source sentences:
text: Some libretti are original stories by the librettist, but very often they are based on a book by another writer.
text: Some libretti are original stories by the librettist, but very often they are based on a book by another writer.
text: Some libretti are original stories by the librettist, but very often they are based on a book by another writer.