Perhaps you should try some spelling variations:
income distributions » time distributions, discrete distributions, size distributions
70 developing » 10 developing, 30 developing, 40 developing
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: %((((income redistribution) OR (income distribution))) OR (income distributions)) %((70 developing) OR (20 developing)) countries%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((((income redistribution) OR (income distribution))) or (income distributions)) %((70 developing) or (20 developing)) countries%22".
• Adding a wildcard symbol may retrieve word variants: %((((income redistribution) OR (income distribution))) or (income distributions)) %((70 developing) or (20 developing)) countries%22*.