CREATE TABLE table_name_84 (m939_series VARCHAR, m809_series VARCHAR, wheelbase VARCHAR)
Name the M939 series for short wheelbase and M809 series of m817
SELECT m939_series FROM table_name_84 WHERE m809_series = "m817" AND wheelbase = "short"
SELECT m939_series FROM table_name_84 WHERE wheelbase = 'short' AND m809_series = 'm817';