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_68 (propulsion VARCHAR, order_year VARCHAR, manufacturer VARCHAR)

### Question ###
What is the Propulsion for the model offered in 2003-2004 by neoplan usa?

### Accurate SQL ###

SELECT propulsion FROM table_name_68 WHERE order_year = "2003-2004" AND manufacturer = "neoplan usa"