user: Question: who is the producer when the narrator is Katherine Kellgren, the year is before 2013 and the author is Karen Cushman?
Columns: ['Year', 'Title', 'Producer', 'Narrator', 'Author', 'Citation']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [2013.0, 'The Fault in Our Stars', 'Brilliance Audio', 'Kate Rudd', 'John Green', 'Winner']
SQL:

assistant: SELECT "Producer" FROM "Table" WHERE "Narrator" = 'Katherine Kellgren' AND "Year" < 2013.0 AND "Author" = 'Karen Cushman';