Perhaps you should try some spelling variations:
income distributions » income distribution, income redistribution, discrete distributions
time distributions » time distribution, size distributions, time distributed
2f developing » f developing, 2.3 developing, 2.2 developing

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 (time distributions))) OR (stable distributions)) %2f developing countries%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((((income distributions) OR (time distributions))) or (stable distributions)) %2f developing countries%22".
• Adding a wildcard symbol may retrieve word variants: %((((income distributions) OR (time distributions))) or (stable distributions)) %2f developing countries%22*.