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_9 ( district VARCHAR, city_area_km_2__ VARCHAR, serial_no VARCHAR )

### Question ###
What district was the city with an area smaller than 12 square kilometers and a serial number of 35?

### Accurate SQL ###

SELECT district FROM table_name_9 WHERE city_area_km_2__ < 12 AND serial_no = 35