Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
canal irrigation » scale irrigation
export canal » export channel, export bans, export cargo
duty banking » south banking, late banking
veto banking » e banking, weak 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 canal irrigation schemes. ) or ( import ((duty banking) OR (veto banking)) crises. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( export canal irrigation schemes. ) OR ( import ((duty banking) OR (veto banking)) crises. )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( export canal irrigation schemes. ) or ( import ((duty banking) OR (veto banking)) crises. ))".
• Adding a wildcard symbol may retrieve word variants: (( export canal irrigation schemes. ) or ( import ((duty banking) OR (veto banking)) crises. ))*.