Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_91 (series_sorted VARCHAR, released VARCHAR)

### Question ###
What is the series sorted value for the episode released December 2009?

### Accurate SQL ###

SELECT series_sorted FROM table_name_91 WHERE released = "december 2009"