Perhaps you should try some spelling variations:
irrigation system » irrigation systems, irrigation water, irrigation scheme
grid integration » trade integration, data integration
case irrigation » scale irrigation, change irrigation, canal irrigation
_ integration » _ integrated
supply case » supply cost, supply chain, supply curve

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: (( supply ((grid integration) OR (_ integration)) theory. ) OR ( supply case irrigation system. ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( supply ((grid integration) OR (_ integration)) theory. ) or ( supply case irrigation system. ))~".
• Adding a wildcard symbol may retrieve word variants: (( supply ((grid integration) OR (_ integration)) theory. ) or ( supply case irrigation system. ))*.