Perhaps you should try some spelling variations:
income distributions » income redistribution, time distributions, discrete distributions
self developing » relief developing, self development, level developing
2f developing » f developing, 7 developing, turf 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: %((income distributions) OR (income distribution)) %((((2f developing) OR (self developing))) OR (70 developing)) countries%22.
• Adding a wildcard symbol may retrieve word variants: %((income distributions) or (income distribution)) %((((2f developing) or (self developing))) or (70 developing)) countries%22*.