-- Database schema
| perpetrator : Perpetrator_ID [ INT ] primary_key , People_ID [ INT ] perpetrator.People_ID = people.People_ID , Date [ TEXT ] , Year [ INT ] , Location [ TEXT ] , Country [ TEXT ] , Killed [ INT ] , Injured [ INT ] | people : People_ID [ INT ] primary_key , Name [ TEXT ] , Height [ INT ] , Weight [ INT ] , Home Town [ TEXT ] |
-- -- Show the countries that have both perpetrators with injures more than 50 and perpetrators with injures smaller than 20.

SELECT Country FROM perpetrator WHERE Injured  >  50 INTERSECT SELECT Country FROM perpetrator WHERE Injured  <  20;