CREATE TABLE table_26621 ("Reference" TEXT, "Author" TEXT, "Section Size" TEXT, "Violins" FLOAT, "Violas" FLOAT, "Celli" FLOAT, "Basses" FLOAT)

How many cellos are suggested in the reference with section size for 20 players?
SELECT "Celli" FROM table_26621 WHERE "Section Size" = '20 players'
SELECT "Celli" FROM "table_26621" WHERE "Section Size" = '20 players'