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_21 (class_to_1928 VARCHAR, year_s__of_manufacture VARCHAR, class_from_1928 VARCHAR)

### Question ###
Which class to 1928 value had years of manufacture of 1921/23 and class from 1928 of BCi-21?

### Accurate SQL ###

SELECT class_to_1928 FROM table_name_21 WHERE year_s__of_manufacture = "1921/23" AND class_from_1928 = "bci-21"