user: Question: Name the M939 series with M809 series of M817 and M39 series of M51
Columns: ['Type', 'wheelbase', 'M39 series', 'M809 series', 'M939 series']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Cargo (14’)', 'long', 'M54', 'M813', 'M923/925']
SQL:

assistant: SELECT "M939 series" FROM "Table" WHERE "M809 series" = 'M817' AND "M39 series" = 'M51';