In which region can you find the stores located in the state whose median income is no more than 30,000?
median income no more than 30,000 refers to Median Income < 30,000
SELECT T FROM ( SELECT DISTINCT CASE  WHEN T2.`Median Income` < 30000 THEN T1.Region END AS T FROM Regions T1 INNER JOIN `Store Locations` T2 ON T2.StateCode = T1.StateCode ) WHERE T IS NOT NULL