Perhaps you should try some spelling variations:
22income distribution » income distribution, income redistribution, income distributional
development countries » developing countries, developed countries, development country
income distributions » income distribution, income redistribution, time distributions
genome distribution » genomic distribution, gene distribution, monomer distribution
zone distribution » one distribution, dose distribution, age distribution

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 (((genome distribution) OR (zone distribution))))) OR (income distributions)) %2 development countries%22.
• Adding a wildcard symbol may retrieve word variants: %((((22income distribution) or (((genome distribution) or (zone distribution))))) or (income distributions)) %2 development countries%22*.