Perhaps you should try some spelling variations:
income distributions » income redistribution, size distributions, stable distributions
time distributions » time distribution, size distributions, stable distributions
72 developing » 7.2 developing, 762 developing, 2 developing
f developing » self developing, turf developing, 2.1 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 distribution) OR (((((income distributions) OR (time distributions))) OR (discrete distributions)))) %((72 developing) OR (f developing)) countries%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((income distribution) or (((((income distributions) OR (time distributions))) or (discrete distributions)))) %((72 developing) or (f developing)) countries%22".
• Adding a wildcard symbol may retrieve word variants: %((income distribution) or (((((income distributions) OR (time distributions))) or (discrete distributions)))) %((72 developing) or (f developing)) countries%22*.