CREATE TABLE table_73440 ("Conference" TEXT, "Regular Season Winner" TEXT, "Conference Player of the Year" TEXT, "Conference Tournament" TEXT, "Tournament Venue  ( City ) " TEXT, "Tournament Winner" TEXT)

Who won the regular season when Missouri Valley Conference took place?
SELECT "Regular Season Winner" FROM table_73440 WHERE "Conference" = 'Missouri Valley Conference'
SELECT "Regular Season Winner" FROM "table_73440" WHERE "Conference" = 'Missouri Valley Conference'