Perhaps you should try some spelling variations:
22income distribution » income distribution, income redistribution, genome distribution
income distributions » income distribution, income redistribution, size distributions
time distributions » time distribution, size distributions, stable distributions
2f developing » f developing, 2.1 developing, self 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 distributions) OR (discrete distributions))))) OR (time distributions)) %2f developing countries%22*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((((22income distribution) or (((income distributions) OR (discrete distributions))))) or (time distributions)) %2f developing countries%22*".