CREATE TABLE film_market_estimation (estimation_id DECIMAL, low_estimate DECIMAL, high_estimate DECIMAL, film_id DECIMAL, type TEXT, market_id DECIMAL, year DECIMAL)
CREATE TABLE film (film_id DECIMAL, title TEXT, studio TEXT, director TEXT, gross_in_dollar DECIMAL)
CREATE TABLE market (market_id DECIMAL, country TEXT, number_cities DECIMAL)

List the names of studios that have at least two films.
SELECT studio FROM film GROUP BY studio HAVING COUNT(*) >= 2
SELECT "studio" FROM "film" GROUP BY "studio" HAVING COUNT(*) >= 2