Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
ratios irrigation » migration irrigation, national irrigation, gravity irrigation
export ratios » export ratio, export duties
data banking » data taking, data linking, data asking
late banking » state banking, water banking, large banking

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( export ratios irrigation schemes. ) or ( import ((data banking) OR (late banking)) services. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( export ratios irrigation schemes. ) OR ( import ((data banking) OR (late banking)) services. ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( export ratios irrigation schemes. ) or ( import ((data banking) OR (late banking)) services. ))*".