user: Question: How many cellos are suggested in the reference with section size for 20 players?
Columns: ['Reference', 'Author', 'Section Size', 'Violins', 'Violas', 'Celli', 'Basses']
Types: ['text', 'text', 'text', 'real', 'real', 'real', 'real']
Sample row: ['"Arranged By Nelson Riddle"', 'Nelson Riddle', '12 players', 8.0, 2.0, 2.0, 0.0]
SQL:

assistant: SELECT "Celli" FROM "Table" WHERE "Section Size" = '20 players';