Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
bans irrigation » canal irrigation, basin irrigation, farm irrigation
state banking » state planning, state banks, state bank
data banking » data linking, late banking, data handling
export bans » export base, export bias, import bans

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

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