Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_18138132_2 (function VARCHAR, release_date VARCHAR)
### Question:
What functions were released on 2011-06-23? 
### Answer:
SELECT function FROM table_18138132_2 WHERE release_date = "2011-06-23"