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_10528691_4 ( model INTEGER, introduction VARCHAR )

### Question ###
What is the model number introduced May 1999?

### Accurate SQL ###

SELECT MAX(model) FROM table_10528691_4 WHERE introduction = "May 1999"