Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
integration south » integration study, integration some, integration social
based irrigation » basin irrigation, water irrigation, led irrigation
supplies based » supplies closed, supplies shared, species based
export trade » export taxes, export base, export tax

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: (( export trade integration south. ) OR ( supplies based irrigation schemes. ))~.
• Adding a wildcard symbol may retrieve word variants: (( export trade integration south. ) or ( supplies based irrigation schemes. ))*.