Perhaps you should try some spelling variations:
22income distribution » income distribution, income redistribution, genome distribution
income distributions » income distribution, income redistribution, time distributions
70 developing » 10 developing, 30 developing, 7.2 developing
40 developing » 10 developing, 30 developing, 40 development
20 developing » 10 developing, 20 development

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: %((22income distribution) OR (income distributions)) %((((70 developing) OR (40 developing))) OR (20 developing)) countries%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((22income distribution) or (income distributions)) %((((70 developing) OR (40 developing))) or (20 developing)) countries%22".
• Adding a wildcard symbol may retrieve word variants: %((22income distribution) or (income distributions)) %((((70 developing) OR (40 developing))) or (20 developing)) countries%22*.