Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
canal irrigation » scale irrigation
linking crises » banking crises, linking chipset, thinking crisis
export canal » export channel, export bans, export cargo
duty linking » data linking, city linking, study linking
import duty » import duties

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 linking crises. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( export canal irrigation schemes. ) OR ( import duty linking crises. )).
• Adding a wildcard symbol may retrieve word variants: (( export canal irrigation schemes. ) or ( import duty linking crises. ))*.