CREATE TABLE table_2209 ("ILO code" TEXT, "Field" TEXT, "conclusion date" TEXT, "entry into force" TEXT, "closure for signature" TEXT, "Parties  ( April 2011 ) " FLOAT, "Denunciations  ( September 2011 ) " FLOAT, "revising convention ( s ) " TEXT, "text and ratifications" TEXT)

What was the revising convention of the field 'trimmers and stokers'?
SELECT "revising convention(s)" FROM table_2209 WHERE "Field" = 'trimmers and stokers'
SELECT "revising convention(s)" FROM "table_2209" WHERE "Field" = 'trimmers and stokers'