Perhaps you should try some spelling variations:
22income distribution » income distributions, income redistribution, genome distribution
self developing » relief developing, self development, level developing
7.2 developing » 5.2 developing, 3.2 developing, 12 developing
70 developing » 10 developing, 20 developing, 30 developing

Try widening your search to All Fields.

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 distribution)) %((((7.2 developing) OR (self developing))) OR (70 developing)) countries%22.
• Adding a wildcard symbol may retrieve word variants: %((22income distribution) or (income distribution)) %((((7.2 developing) or (self developing))) or (70 developing)) countries%22*.