Perhaps you should try some spelling variations:
integration efforts » international efforts, conservation efforts
irrigation schemes » irrigation scheme, irrigation systems
gray irrigation » grain irrigation, gravity irrigation, murray irrigation
supply trade » supply case
supply gray » supply great, supply gap, supply gas

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( supply trade integration efforts. ) or ( supply gray irrigation schemes. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply trade integration efforts. ) OR ( supply gray irrigation schemes. )).
• Adding a wildcard symbol may retrieve word variants: (( supply trade integration efforts. ) or ( supply gray irrigation schemes. ))*.