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