CREATE TABLE table_18943444_1 (producer VARCHAR, product VARCHAR)

Who is the producer of ?
SELECT producer FROM table_18943444_1 WHERE product = "金必氏牌嬰幼兒配方乳粉"
SELECT "producer" FROM "table_18943444_1" WHERE "product" = "金必氏牌嬰幼兒配方乳粉"